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This commit is contained in:
@@ -43,61 +43,210 @@ $$
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=== "Python"
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```python title="min_cost_climbing_stairs_dp.py"
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[class]{}-[func]{min_cost_climbing_stairs_dp}
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def min_cost_climbing_stairs_dp(cost: list[int]) -> int:
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"""爬楼梯最小代价:动态规划"""
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n = len(cost) - 1
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if n == 1 or n == 2:
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return cost[n]
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# 初始化 dp 表,用于存储子问题的解
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dp = [0] * (n + 1)
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# 初始状态:预设最小子问题的解
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dp[1], dp[2] = cost[1], cost[2]
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# 状态转移:从较小子问题逐步求解较大子问题
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for i in range(3, n + 1):
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dp[i] = min(dp[i - 1], dp[i - 2]) + cost[i]
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return dp[n]
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```
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=== "C++"
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```cpp title="min_cost_climbing_stairs_dp.cpp"
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[class]{}-[func]{minCostClimbingStairsDP}
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/* 爬楼梯最小代价:动态规划 */
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int minCostClimbingStairsDP(vector<int> &cost) {
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int n = cost.size() - 1;
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if (n == 1 || n == 2)
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return cost[n];
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// 初始化 dp 表,用于存储子问题的解
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vector<int> dp(n + 1);
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// 初始状态:预设最小子问题的解
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dp[1] = cost[1];
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dp[2] = cost[2];
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// 状态转移:从较小子问题逐步求解较大子问题
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for (int i = 3; i <= n; i++) {
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dp[i] = min(dp[i - 1], dp[i - 2]) + cost[i];
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}
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return dp[n];
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}
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```
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=== "Java"
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```java title="min_cost_climbing_stairs_dp.java"
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[class]{min_cost_climbing_stairs_dp}-[func]{minCostClimbingStairsDP}
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/* 爬楼梯最小代价:动态规划 */
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int minCostClimbingStairsDP(int[] cost) {
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int n = cost.length - 1;
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if (n == 1 || n == 2)
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return cost[n];
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// 初始化 dp 表,用于存储子问题的解
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int[] dp = new int[n + 1];
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// 初始状态:预设最小子问题的解
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dp[1] = cost[1];
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dp[2] = cost[2];
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// 状态转移:从较小子问题逐步求解较大子问题
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for (int i = 3; i <= n; i++) {
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dp[i] = Math.min(dp[i - 1], dp[i - 2]) + cost[i];
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}
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return dp[n];
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}
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```
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=== "C#"
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```csharp title="min_cost_climbing_stairs_dp.cs"
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[class]{min_cost_climbing_stairs_dp}-[func]{minCostClimbingStairsDP}
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/* 爬楼梯最小代价:动态规划 */
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int minCostClimbingStairsDP(int[] cost) {
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int n = cost.Length - 1;
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if (n == 1 || n == 2)
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return cost[n];
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// 初始化 dp 表,用于存储子问题的解
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int[] dp = new int[n + 1];
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// 初始状态:预设最小子问题的解
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dp[1] = cost[1];
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dp[2] = cost[2];
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// 状态转移:从较小子问题逐步求解较大子问题
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for (int i = 3; i <= n; i++) {
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dp[i] = Math.Min(dp[i - 1], dp[i - 2]) + cost[i];
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}
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return dp[n];
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}
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```
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=== "Go"
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```go title="min_cost_climbing_stairs_dp.go"
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[class]{}-[func]{minCostClimbingStairsDP}
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/* 爬楼梯最小代价:动态规划 */
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func minCostClimbingStairsDP(cost []int) int {
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n := len(cost) - 1
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if n == 1 || n == 2 {
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return cost[n]
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}
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// 初始化 dp 表,用于存储子问题的解
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dp := make([]int, n+1)
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// 初始状态:预设最小子问题的解
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dp[1] = cost[1]
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dp[2] = cost[2]
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// 状态转移:从较小子问题逐步求解较大子问题
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for i := 3; i <= n; i++ {
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dp[i] = int(math.Min(float64(dp[i-1]), float64(dp[i-2]+cost[i])))
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}
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return dp[n]
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}
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```
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=== "Swift"
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```swift title="min_cost_climbing_stairs_dp.swift"
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[class]{}-[func]{minCostClimbingStairsDP}
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/* 爬楼梯最小代价:动态规划 */
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func minCostClimbingStairsDP(cost: [Int]) -> Int {
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let n = cost.count - 1
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if n == 1 || n == 2 {
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return cost[n]
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}
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// 初始化 dp 表,用于存储子问题的解
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var dp = Array(repeating: 0, count: n + 1)
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// 初始状态:预设最小子问题的解
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dp[1] = cost[1]
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dp[2] = cost[2]
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// 状态转移:从较小子问题逐步求解较大子问题
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for i in stride(from: 3, through: n, by: 1) {
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dp[i] = min(dp[i - 1], dp[i - 2]) + cost[i]
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}
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return dp[n]
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}
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```
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=== "JS"
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```javascript title="min_cost_climbing_stairs_dp.js"
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[class]{}-[func]{minCostClimbingStairsDP}
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/* 爬楼梯最小代价:动态规划 */
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function minCostClimbingStairsDP(cost) {
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const n = cost.length - 1;
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if (n === 1 || n === 2) {
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return cost[n];
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}
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// 初始化 dp 表,用于存储子问题的解
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const dp = new Array(n + 1);
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// 初始状态:预设最小子问题的解
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dp[1] = cost[1];
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dp[2] = cost[2];
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// 状态转移:从较小子问题逐步求解较大子问题
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for (let i = 3; i <= n; i++) {
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dp[i] = Math.min(dp[i - 1], dp[i - 2]) + cost[i];
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}
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return dp[n];
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}
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```
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=== "TS"
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||||
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```typescript title="min_cost_climbing_stairs_dp.ts"
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[class]{}-[func]{minCostClimbingStairsDP}
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/* 爬楼梯最小代价:动态规划 */
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function minCostClimbingStairsDP(cost: Array<number>): number {
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const n = cost.length - 1;
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if (n === 1 || n === 2) {
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return cost[n];
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}
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// 初始化 dp 表,用于存储子问题的解
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const dp = new Array(n + 1);
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// 初始状态:预设最小子问题的解
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dp[1] = cost[1];
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dp[2] = cost[2];
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// 状态转移:从较小子问题逐步求解较大子问题
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for (let i = 3; i <= n; i++) {
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dp[i] = Math.min(dp[i - 1], dp[i - 2]) + cost[i];
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}
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return dp[n];
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}
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```
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=== "Dart"
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```dart title="min_cost_climbing_stairs_dp.dart"
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[class]{}-[func]{minCostClimbingStairsDP}
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/* 爬楼梯最小代价:动态规划 */
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int minCostClimbingStairsDP(List<int> cost) {
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int n = cost.length - 1;
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if (n == 1 || n == 2) return cost[n];
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// 初始化 dp 表,用于存储子问题的解
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List<int> dp = List.filled(n + 1, 0);
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// 初始状态:预设最小子问题的解
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dp[1] = cost[1];
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dp[2] = cost[2];
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// 状态转移:从较小子问题逐步求解较大子问题
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for (int i = 3; i <= n; i++) {
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dp[i] = min(dp[i - 1], dp[i - 2]) + cost[i];
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}
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return dp[n];
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}
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```
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=== "Rust"
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```rust title="min_cost_climbing_stairs_dp.rs"
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[class]{}-[func]{min_cost_climbing_stairs_dp}
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/* 爬楼梯最小代价:动态规划 */
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fn min_cost_climbing_stairs_dp(cost: &[i32]) -> i32 {
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let n = cost.len() - 1;
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if n == 1 || n == 2 { return cost[n]; }
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// 初始化 dp 表,用于存储子问题的解
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let mut dp = vec![-1; n + 1];
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// 初始状态:预设最小子问题的解
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dp[1] = cost[1];
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dp[2] = cost[2];
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// 状态转移:从较小子问题逐步求解较大子问题
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for i in 3..=n {
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dp[i] = cmp::min(dp[i - 1], dp[i - 2]) + cost[i];
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}
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dp[n]
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}
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```
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=== "C"
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@@ -109,7 +258,23 @@ $$
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=== "Zig"
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```zig title="min_cost_climbing_stairs_dp.zig"
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[class]{}-[func]{minCostClimbingStairsDP}
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// 爬楼梯最小代价:动态规划
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fn minCostClimbingStairsDP(comptime cost: []i32) i32 {
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comptime var n = cost.len - 1;
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if (n == 1 or n == 2) {
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return cost[n];
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}
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// 初始化 dp 表,用于存储子问题的解
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var dp = [_]i32{-1} ** (n + 1);
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// 初始状态:预设最小子问题的解
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dp[1] = cost[1];
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dp[2] = cost[2];
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// 状态转移:从较小子问题逐步求解较大子问题
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for (3..n + 1) |i| {
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dp[i] = @min(dp[i - 1], dp[i - 2]) + cost[i];
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}
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return dp[n];
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}
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```
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图 14-7 展示了以上代码的动态规划过程。
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@@ -123,61 +288,181 @@ $$
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=== "Python"
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```python title="min_cost_climbing_stairs_dp.py"
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[class]{}-[func]{min_cost_climbing_stairs_dp_comp}
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def min_cost_climbing_stairs_dp_comp(cost: list[int]) -> int:
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"""爬楼梯最小代价:空间优化后的动态规划"""
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n = len(cost) - 1
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if n == 1 or n == 2:
|
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return cost[n]
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a, b = cost[1], cost[2]
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for i in range(3, n + 1):
|
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a, b = b, min(a, b) + cost[i]
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return b
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```
|
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|
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=== "C++"
|
||||
|
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```cpp title="min_cost_climbing_stairs_dp.cpp"
|
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[class]{}-[func]{minCostClimbingStairsDPComp}
|
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/* 爬楼梯最小代价:空间优化后的动态规划 */
|
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int minCostClimbingStairsDPComp(vector<int> &cost) {
|
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int n = cost.size() - 1;
|
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if (n == 1 || n == 2)
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return cost[n];
|
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int a = cost[1], b = cost[2];
|
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for (int i = 3; i <= n; i++) {
|
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int tmp = b;
|
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b = min(a, tmp) + cost[i];
|
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a = tmp;
|
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}
|
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return b;
|
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}
|
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```
|
||||
|
||||
=== "Java"
|
||||
|
||||
```java title="min_cost_climbing_stairs_dp.java"
|
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[class]{min_cost_climbing_stairs_dp}-[func]{minCostClimbingStairsDPComp}
|
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/* 爬楼梯最小代价:空间优化后的动态规划 */
|
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int minCostClimbingStairsDPComp(int[] cost) {
|
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int n = cost.length - 1;
|
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if (n == 1 || n == 2)
|
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return cost[n];
|
||||
int a = cost[1], b = cost[2];
|
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for (int i = 3; i <= n; i++) {
|
||||
int tmp = b;
|
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b = Math.min(a, tmp) + cost[i];
|
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a = tmp;
|
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}
|
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return b;
|
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}
|
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```
|
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|
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=== "C#"
|
||||
|
||||
```csharp title="min_cost_climbing_stairs_dp.cs"
|
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[class]{min_cost_climbing_stairs_dp}-[func]{minCostClimbingStairsDPComp}
|
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/* 爬楼梯最小代价:空间优化后的动态规划 */
|
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int minCostClimbingStairsDPComp(int[] cost) {
|
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int n = cost.Length - 1;
|
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if (n == 1 || n == 2)
|
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return cost[n];
|
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int a = cost[1], b = cost[2];
|
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for (int i = 3; i <= n; i++) {
|
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int tmp = b;
|
||||
b = Math.Min(a, tmp) + cost[i];
|
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a = tmp;
|
||||
}
|
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return b;
|
||||
}
|
||||
```
|
||||
|
||||
=== "Go"
|
||||
|
||||
```go title="min_cost_climbing_stairs_dp.go"
|
||||
[class]{}-[func]{minCostClimbingStairsDPComp}
|
||||
/* 爬楼梯最小代价:空间优化后的动态规划 */
|
||||
func minCostClimbingStairsDPComp(cost []int) int {
|
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n := len(cost) - 1
|
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if n == 1 || n == 2 {
|
||||
return cost[n]
|
||||
}
|
||||
// 初始状态:预设最小子问题的解
|
||||
a, b := cost[1], cost[2]
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for i := 3; i <= n; i++ {
|
||||
tmp := b
|
||||
b = int(math.Min(float64(a), float64(tmp+cost[i])))
|
||||
a = tmp
|
||||
}
|
||||
return b
|
||||
}
|
||||
```
|
||||
|
||||
=== "Swift"
|
||||
|
||||
```swift title="min_cost_climbing_stairs_dp.swift"
|
||||
[class]{}-[func]{minCostClimbingStairsDPComp}
|
||||
/* 爬楼梯最小代价:空间优化后的动态规划 */
|
||||
func minCostClimbingStairsDPComp(cost: [Int]) -> Int {
|
||||
let n = cost.count - 1
|
||||
if n == 1 || n == 2 {
|
||||
return cost[n]
|
||||
}
|
||||
var (a, b) = (cost[1], cost[2])
|
||||
for i in stride(from: 3, through: n, by: 1) {
|
||||
(a, b) = (b, min(a, b) + cost[i])
|
||||
}
|
||||
return b
|
||||
}
|
||||
```
|
||||
|
||||
=== "JS"
|
||||
|
||||
```javascript title="min_cost_climbing_stairs_dp.js"
|
||||
[class]{}-[func]{minCostClimbingStairsDPComp}
|
||||
/* 爬楼梯最小代价:状态压缩后的动态规划 */
|
||||
function minCostClimbingStairsDPComp(cost) {
|
||||
const n = cost.length - 1;
|
||||
if (n === 1 || n === 2) {
|
||||
return cost[n];
|
||||
}
|
||||
let a = cost[1],
|
||||
b = cost[2];
|
||||
for (let i = 3; i <= n; i++) {
|
||||
const tmp = b;
|
||||
b = Math.min(a, tmp) + cost[i];
|
||||
a = tmp;
|
||||
}
|
||||
return b;
|
||||
}
|
||||
```
|
||||
|
||||
=== "TS"
|
||||
|
||||
```typescript title="min_cost_climbing_stairs_dp.ts"
|
||||
[class]{}-[func]{minCostClimbingStairsDPComp}
|
||||
/* 爬楼梯最小代价:状态压缩后的动态规划 */
|
||||
function minCostClimbingStairsDPComp(cost: Array<number>): number {
|
||||
const n = cost.length - 1;
|
||||
if (n === 1 || n === 2) {
|
||||
return cost[n];
|
||||
}
|
||||
let a = cost[1],
|
||||
b = cost[2];
|
||||
for (let i = 3; i <= n; i++) {
|
||||
const tmp = b;
|
||||
b = Math.min(a, tmp) + cost[i];
|
||||
a = tmp;
|
||||
}
|
||||
return b;
|
||||
}
|
||||
```
|
||||
|
||||
=== "Dart"
|
||||
|
||||
```dart title="min_cost_climbing_stairs_dp.dart"
|
||||
[class]{}-[func]{minCostClimbingStairsDPComp}
|
||||
/* 爬楼梯最小代价:空间优化后的动态规划 */
|
||||
int minCostClimbingStairsDPComp(List<int> cost) {
|
||||
int n = cost.length - 1;
|
||||
if (n == 1 || n == 2) return cost[n];
|
||||
int a = cost[1], b = cost[2];
|
||||
for (int i = 3; i <= n; i++) {
|
||||
int tmp = b;
|
||||
b = min(a, tmp) + cost[i];
|
||||
a = tmp;
|
||||
}
|
||||
return b;
|
||||
}
|
||||
```
|
||||
|
||||
=== "Rust"
|
||||
|
||||
```rust title="min_cost_climbing_stairs_dp.rs"
|
||||
[class]{}-[func]{min_cost_climbing_stairs_dp_comp}
|
||||
/* 爬楼梯最小代价:空间优化后的动态规划 */
|
||||
fn min_cost_climbing_stairs_dp_comp(cost: &[i32]) -> i32 {
|
||||
let n = cost.len() - 1;
|
||||
if n == 1 || n == 2 { return cost[n] };
|
||||
let (mut a, mut b) = (cost[1], cost[2]);
|
||||
for i in 3..=n {
|
||||
let tmp = b;
|
||||
b = cmp::min(a, tmp) + cost[i];
|
||||
a = tmp;
|
||||
}
|
||||
b
|
||||
}
|
||||
```
|
||||
|
||||
=== "C"
|
||||
@@ -189,7 +474,22 @@ $$
|
||||
=== "Zig"
|
||||
|
||||
```zig title="min_cost_climbing_stairs_dp.zig"
|
||||
[class]{}-[func]{minCostClimbingStairsDPComp}
|
||||
// 爬楼梯最小代价:空间优化后的动态规划
|
||||
fn minCostClimbingStairsDPComp(cost: []i32) i32 {
|
||||
var n = cost.len - 1;
|
||||
if (n == 1 or n == 2) {
|
||||
return cost[n];
|
||||
}
|
||||
var a = cost[1];
|
||||
var b = cost[2];
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for (3..n + 1) |i| {
|
||||
var tmp = b;
|
||||
b = @min(a, tmp) + cost[i];
|
||||
a = tmp;
|
||||
}
|
||||
return b;
|
||||
}
|
||||
```
|
||||
|
||||
## 14.2.2 无后效性
|
||||
@@ -237,61 +537,234 @@ $$
|
||||
=== "Python"
|
||||
|
||||
```python title="climbing_stairs_constraint_dp.py"
|
||||
[class]{}-[func]{climbing_stairs_constraint_dp}
|
||||
def climbing_stairs_constraint_dp(n: int) -> int:
|
||||
"""带约束爬楼梯:动态规划"""
|
||||
if n == 1 or n == 2:
|
||||
return 1
|
||||
# 初始化 dp 表,用于存储子问题的解
|
||||
dp = [[0] * 3 for _ in range(n + 1)]
|
||||
# 初始状态:预设最小子问题的解
|
||||
dp[1][1], dp[1][2] = 1, 0
|
||||
dp[2][1], dp[2][2] = 0, 1
|
||||
# 状态转移:从较小子问题逐步求解较大子问题
|
||||
for i in range(3, n + 1):
|
||||
dp[i][1] = dp[i - 1][2]
|
||||
dp[i][2] = dp[i - 2][1] + dp[i - 2][2]
|
||||
return dp[n][1] + dp[n][2]
|
||||
```
|
||||
|
||||
=== "C++"
|
||||
|
||||
```cpp title="climbing_stairs_constraint_dp.cpp"
|
||||
[class]{}-[func]{climbingStairsConstraintDP}
|
||||
/* 带约束爬楼梯:动态规划 */
|
||||
int climbingStairsConstraintDP(int n) {
|
||||
if (n == 1 || n == 2) {
|
||||
return 1;
|
||||
}
|
||||
// 初始化 dp 表,用于存储子问题的解
|
||||
vector<vector<int>> dp(n + 1, vector<int>(3, 0));
|
||||
// 初始状态:预设最小子问题的解
|
||||
dp[1][1] = 1;
|
||||
dp[1][2] = 0;
|
||||
dp[2][1] = 0;
|
||||
dp[2][2] = 1;
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for (int i = 3; i <= n; i++) {
|
||||
dp[i][1] = dp[i - 1][2];
|
||||
dp[i][2] = dp[i - 2][1] + dp[i - 2][2];
|
||||
}
|
||||
return dp[n][1] + dp[n][2];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Java"
|
||||
|
||||
```java title="climbing_stairs_constraint_dp.java"
|
||||
[class]{climbing_stairs_constraint_dp}-[func]{climbingStairsConstraintDP}
|
||||
/* 带约束爬楼梯:动态规划 */
|
||||
int climbingStairsConstraintDP(int n) {
|
||||
if (n == 1 || n == 2) {
|
||||
return 1;
|
||||
}
|
||||
// 初始化 dp 表,用于存储子问题的解
|
||||
int[][] dp = new int[n + 1][3];
|
||||
// 初始状态:预设最小子问题的解
|
||||
dp[1][1] = 1;
|
||||
dp[1][2] = 0;
|
||||
dp[2][1] = 0;
|
||||
dp[2][2] = 1;
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for (int i = 3; i <= n; i++) {
|
||||
dp[i][1] = dp[i - 1][2];
|
||||
dp[i][2] = dp[i - 2][1] + dp[i - 2][2];
|
||||
}
|
||||
return dp[n][1] + dp[n][2];
|
||||
}
|
||||
```
|
||||
|
||||
=== "C#"
|
||||
|
||||
```csharp title="climbing_stairs_constraint_dp.cs"
|
||||
[class]{climbing_stairs_constraint_dp}-[func]{climbingStairsConstraintDP}
|
||||
/* 带约束爬楼梯:动态规划 */
|
||||
int climbingStairsConstraintDP(int n) {
|
||||
if (n == 1 || n == 2) {
|
||||
return 1;
|
||||
}
|
||||
// 初始化 dp 表,用于存储子问题的解
|
||||
int[,] dp = new int[n + 1, 3];
|
||||
// 初始状态:预设最小子问题的解
|
||||
dp[1, 1] = 1;
|
||||
dp[1, 2] = 0;
|
||||
dp[2, 1] = 0;
|
||||
dp[2, 2] = 1;
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for (int i = 3; i <= n; i++) {
|
||||
dp[i, 1] = dp[i - 1, 2];
|
||||
dp[i, 2] = dp[i - 2, 1] + dp[i - 2, 2];
|
||||
}
|
||||
return dp[n, 1] + dp[n, 2];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Go"
|
||||
|
||||
```go title="climbing_stairs_constraint_dp.go"
|
||||
[class]{}-[func]{climbingStairsConstraintDP}
|
||||
/* 带约束爬楼梯:动态规划 */
|
||||
func climbingStairsConstraintDP(n int) int {
|
||||
if n == 1 || n == 2 {
|
||||
return 1
|
||||
}
|
||||
// 初始化 dp 表,用于存储子问题的解
|
||||
dp := make([][3]int, n+1)
|
||||
// 初始状态:预设最小子问题的解
|
||||
dp[1][1] = 1
|
||||
dp[1][2] = 0
|
||||
dp[2][1] = 0
|
||||
dp[2][2] = 1
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for i := 3; i <= n; i++ {
|
||||
dp[i][1] = dp[i-1][2]
|
||||
dp[i][2] = dp[i-2][1] + dp[i-2][2]
|
||||
}
|
||||
return dp[n][1] + dp[n][2]
|
||||
}
|
||||
```
|
||||
|
||||
=== "Swift"
|
||||
|
||||
```swift title="climbing_stairs_constraint_dp.swift"
|
||||
[class]{}-[func]{climbingStairsConstraintDP}
|
||||
/* 带约束爬楼梯:动态规划 */
|
||||
func climbingStairsConstraintDP(n: Int) -> Int {
|
||||
if n == 1 || n == 2 {
|
||||
return 1
|
||||
}
|
||||
// 初始化 dp 表,用于存储子问题的解
|
||||
var dp = Array(repeating: Array(repeating: 0, count: 3), count: n + 1)
|
||||
// 初始状态:预设最小子问题的解
|
||||
dp[1][1] = 1
|
||||
dp[1][2] = 0
|
||||
dp[2][1] = 0
|
||||
dp[2][2] = 1
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for i in stride(from: 3, through: n, by: 1) {
|
||||
dp[i][1] = dp[i - 1][2]
|
||||
dp[i][2] = dp[i - 2][1] + dp[i - 2][2]
|
||||
}
|
||||
return dp[n][1] + dp[n][2]
|
||||
}
|
||||
```
|
||||
|
||||
=== "JS"
|
||||
|
||||
```javascript title="climbing_stairs_constraint_dp.js"
|
||||
[class]{}-[func]{climbingStairsConstraintDP}
|
||||
/* 带约束爬楼梯:动态规划 */
|
||||
function climbingStairsConstraintDP(n) {
|
||||
if (n === 1 || n === 2) {
|
||||
return 1;
|
||||
}
|
||||
// 初始化 dp 表,用于存储子问题的解
|
||||
const dp = Array.from(new Array(n + 1), () => new Array(3));
|
||||
// 初始状态:预设最小子问题的解
|
||||
dp[1][1] = 1;
|
||||
dp[1][2] = 0;
|
||||
dp[2][1] = 0;
|
||||
dp[2][2] = 1;
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for (let i = 3; i <= n; i++) {
|
||||
dp[i][1] = dp[i - 1][2];
|
||||
dp[i][2] = dp[i - 2][1] + dp[i - 2][2];
|
||||
}
|
||||
return dp[n][1] + dp[n][2];
|
||||
}
|
||||
```
|
||||
|
||||
=== "TS"
|
||||
|
||||
```typescript title="climbing_stairs_constraint_dp.ts"
|
||||
[class]{}-[func]{climbingStairsConstraintDP}
|
||||
/* 带约束爬楼梯:动态规划 */
|
||||
function climbingStairsConstraintDP(n: number): number {
|
||||
if (n === 1 || n === 2) {
|
||||
return 1;
|
||||
}
|
||||
// 初始化 dp 表,用于存储子问题的解
|
||||
const dp = Array.from({ length: n + 1 }, () => new Array(3));
|
||||
// 初始状态:预设最小子问题的解
|
||||
dp[1][1] = 1;
|
||||
dp[1][2] = 0;
|
||||
dp[2][1] = 0;
|
||||
dp[2][2] = 1;
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for (let i = 3; i <= n; i++) {
|
||||
dp[i][1] = dp[i - 1][2];
|
||||
dp[i][2] = dp[i - 2][1] + dp[i - 2][2];
|
||||
}
|
||||
return dp[n][1] + dp[n][2];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Dart"
|
||||
|
||||
```dart title="climbing_stairs_constraint_dp.dart"
|
||||
[class]{}-[func]{climbingStairsConstraintDP}
|
||||
/* 带约束爬楼梯:动态规划 */
|
||||
int climbingStairsConstraintDP(int n) {
|
||||
if (n == 1 || n == 2) {
|
||||
return 1;
|
||||
}
|
||||
// 初始化 dp 表,用于存储子问题的解
|
||||
List<List<int>> dp = List.generate(n + 1, (index) => List.filled(3, 0));
|
||||
// 初始状态:预设最小子问题的解
|
||||
dp[1][1] = 1;
|
||||
dp[1][2] = 0;
|
||||
dp[2][1] = 0;
|
||||
dp[2][2] = 1;
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for (int i = 3; i <= n; i++) {
|
||||
dp[i][1] = dp[i - 1][2];
|
||||
dp[i][2] = dp[i - 2][1] + dp[i - 2][2];
|
||||
}
|
||||
return dp[n][1] + dp[n][2];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Rust"
|
||||
|
||||
```rust title="climbing_stairs_constraint_dp.rs"
|
||||
[class]{}-[func]{climbing_stairs_constraint_dp}
|
||||
/* 带约束爬楼梯:动态规划 */
|
||||
fn climbing_stairs_constraint_dp(n: usize) -> i32 {
|
||||
if n == 1 || n == 2 { return 1 };
|
||||
// 初始化 dp 表,用于存储子问题的解
|
||||
let mut dp = vec![vec![-1; 3]; n + 1];
|
||||
// 初始状态:预设最小子问题的解
|
||||
dp[1][1] = 1;
|
||||
dp[1][2] = 0;
|
||||
dp[2][1] = 0;
|
||||
dp[2][2] = 1;
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for i in 3..=n {
|
||||
dp[i][1] = dp[i - 1][2];
|
||||
dp[i][2] = dp[i - 2][1] + dp[i - 2][2];
|
||||
}
|
||||
dp[n][1] + dp[n][2]
|
||||
}
|
||||
```
|
||||
|
||||
=== "C"
|
||||
@@ -303,7 +776,25 @@ $$
|
||||
=== "Zig"
|
||||
|
||||
```zig title="climbing_stairs_constraint_dp.zig"
|
||||
[class]{}-[func]{climbingStairsConstraintDP}
|
||||
// 带约束爬楼梯:动态规划
|
||||
fn climbingStairsConstraintDP(comptime n: usize) i32 {
|
||||
if (n == 1 or n == 2) {
|
||||
return 1;
|
||||
}
|
||||
// 初始化 dp 表,用于存储子问题的解
|
||||
var dp = [_][3]i32{ [_]i32{ -1, -1, -1 } } ** (n + 1);
|
||||
// 初始状态:预设最小子问题的解
|
||||
dp[1][1] = 1;
|
||||
dp[1][2] = 0;
|
||||
dp[2][1] = 0;
|
||||
dp[2][2] = 1;
|
||||
// 状态转移:从较小子问题逐步求解较大子问题
|
||||
for (3..n + 1) |i| {
|
||||
dp[i][1] = dp[i - 1][2];
|
||||
dp[i][2] = dp[i - 2][1] + dp[i - 2][2];
|
||||
}
|
||||
return dp[n][1] + dp[n][2];
|
||||
}
|
||||
```
|
||||
|
||||
在上面的案例中,由于仅需多考虑前面一个状态,我们仍然可以通过扩展状态定义,使得问题重新满足无后效性。然而,某些问题具有非常严重的“有后效性”。
|
||||
|
||||
File diff suppressed because it is too large
Load Diff
@@ -80,61 +80,312 @@ $$
|
||||
=== "Python"
|
||||
|
||||
```python title="edit_distance.py"
|
||||
[class]{}-[func]{edit_distance_dp}
|
||||
def edit_distance_dp(s: str, t: str) -> int:
|
||||
"""编辑距离:动态规划"""
|
||||
n, m = len(s), len(t)
|
||||
dp = [[0] * (m + 1) for _ in range(n + 1)]
|
||||
# 状态转移:首行首列
|
||||
for i in range(1, n + 1):
|
||||
dp[i][0] = i
|
||||
for j in range(1, m + 1):
|
||||
dp[0][j] = j
|
||||
# 状态转移:其余行列
|
||||
for i in range(1, n + 1):
|
||||
for j in range(1, m + 1):
|
||||
if s[i - 1] == t[j - 1]:
|
||||
# 若两字符相等,则直接跳过此两字符
|
||||
dp[i][j] = dp[i - 1][j - 1]
|
||||
else:
|
||||
# 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i][j] = min(dp[i][j - 1], dp[i - 1][j], dp[i - 1][j - 1]) + 1
|
||||
return dp[n][m]
|
||||
```
|
||||
|
||||
=== "C++"
|
||||
|
||||
```cpp title="edit_distance.cpp"
|
||||
[class]{}-[func]{editDistanceDP}
|
||||
/* 编辑距离:动态规划 */
|
||||
int editDistanceDP(string s, string t) {
|
||||
int n = s.length(), m = t.length();
|
||||
vector<vector<int>> dp(n + 1, vector<int>(m + 1, 0));
|
||||
// 状态转移:首行首列
|
||||
for (int i = 1; i <= n; i++) {
|
||||
dp[i][0] = i;
|
||||
}
|
||||
for (int j = 1; j <= m; j++) {
|
||||
dp[0][j] = j;
|
||||
}
|
||||
// 状态转移:其余行列
|
||||
for (int i = 1; i <= n; i++) {
|
||||
for (int j = 1; j <= m; j++) {
|
||||
if (s[i - 1] == t[j - 1]) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[i][j] = dp[i - 1][j - 1];
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i][j] = min(min(dp[i][j - 1], dp[i - 1][j]), dp[i - 1][j - 1]) + 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[n][m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Java"
|
||||
|
||||
```java title="edit_distance.java"
|
||||
[class]{edit_distance}-[func]{editDistanceDP}
|
||||
/* 编辑距离:动态规划 */
|
||||
int editDistanceDP(String s, String t) {
|
||||
int n = s.length(), m = t.length();
|
||||
int[][] dp = new int[n + 1][m + 1];
|
||||
// 状态转移:首行首列
|
||||
for (int i = 1; i <= n; i++) {
|
||||
dp[i][0] = i;
|
||||
}
|
||||
for (int j = 1; j <= m; j++) {
|
||||
dp[0][j] = j;
|
||||
}
|
||||
// 状态转移:其余行列
|
||||
for (int i = 1; i <= n; i++) {
|
||||
for (int j = 1; j <= m; j++) {
|
||||
if (s.charAt(i - 1) == t.charAt(j - 1)) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[i][j] = dp[i - 1][j - 1];
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i][j] = Math.min(Math.min(dp[i][j - 1], dp[i - 1][j]), dp[i - 1][j - 1]) + 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[n][m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "C#"
|
||||
|
||||
```csharp title="edit_distance.cs"
|
||||
[class]{edit_distance}-[func]{editDistanceDP}
|
||||
/* 编辑距离:动态规划 */
|
||||
int editDistanceDP(string s, string t) {
|
||||
int n = s.Length, m = t.Length;
|
||||
int[,] dp = new int[n + 1, m + 1];
|
||||
// 状态转移:首行首列
|
||||
for (int i = 1; i <= n; i++) {
|
||||
dp[i, 0] = i;
|
||||
}
|
||||
for (int j = 1; j <= m; j++) {
|
||||
dp[0, j] = j;
|
||||
}
|
||||
// 状态转移:其余行列
|
||||
for (int i = 1; i <= n; i++) {
|
||||
for (int j = 1; j <= m; j++) {
|
||||
if (s[i - 1] == t[j - 1]) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[i, j] = dp[i - 1, j - 1];
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i, j] = Math.Min(Math.Min(dp[i, j - 1], dp[i - 1, j]), dp[i - 1, j - 1]) + 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[n, m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Go"
|
||||
|
||||
```go title="edit_distance.go"
|
||||
[class]{}-[func]{editDistanceDP}
|
||||
/* 编辑距离:动态规划 */
|
||||
func editDistanceDP(s string, t string) int {
|
||||
n := len(s)
|
||||
m := len(t)
|
||||
dp := make([][]int, n+1)
|
||||
for i := 0; i <= n; i++ {
|
||||
dp[i] = make([]int, m+1)
|
||||
}
|
||||
// 状态转移:首行首列
|
||||
for i := 1; i <= n; i++ {
|
||||
dp[i][0] = i
|
||||
}
|
||||
for j := 1; j <= m; j++ {
|
||||
dp[0][j] = j
|
||||
}
|
||||
// 状态转移:其余行列
|
||||
for i := 1; i <= n; i++ {
|
||||
for j := 1; j <= m; j++ {
|
||||
if s[i-1] == t[j-1] {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[i][j] = dp[i-1][j-1]
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i][j] = MinInt(MinInt(dp[i][j-1], dp[i-1][j]), dp[i-1][j-1]) + 1
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[n][m]
|
||||
}
|
||||
```
|
||||
|
||||
=== "Swift"
|
||||
|
||||
```swift title="edit_distance.swift"
|
||||
[class]{}-[func]{editDistanceDP}
|
||||
/* 编辑距离:动态规划 */
|
||||
func editDistanceDP(s: String, t: String) -> Int {
|
||||
let n = s.utf8CString.count
|
||||
let m = t.utf8CString.count
|
||||
var dp = Array(repeating: Array(repeating: 0, count: m + 1), count: n + 1)
|
||||
// 状态转移:首行首列
|
||||
for i in stride(from: 1, through: n, by: 1) {
|
||||
dp[i][0] = i
|
||||
}
|
||||
for j in stride(from: 1, through: m, by: 1) {
|
||||
dp[0][j] = j
|
||||
}
|
||||
// 状态转移:其余行列
|
||||
for i in stride(from: 1, through: n, by: 1) {
|
||||
for j in stride(from: 1, through: m, by: 1) {
|
||||
if s.utf8CString[i - 1] == t.utf8CString[j - 1] {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[i][j] = dp[i - 1][j - 1]
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i][j] = min(min(dp[i][j - 1], dp[i - 1][j]), dp[i - 1][j - 1]) + 1
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[n][m]
|
||||
}
|
||||
```
|
||||
|
||||
=== "JS"
|
||||
|
||||
```javascript title="edit_distance.js"
|
||||
[class]{}-[func]{editDistanceDP}
|
||||
/* 编辑距离:动态规划 */
|
||||
function editDistanceDP(s, t) {
|
||||
const n = s.length,
|
||||
m = t.length;
|
||||
const dp = Array.from({ length: n + 1 }, () => new Array(m + 1).fill(0));
|
||||
// 状态转移:首行首列
|
||||
for (let i = 1; i <= n; i++) {
|
||||
dp[i][0] = i;
|
||||
}
|
||||
for (let j = 1; j <= m; j++) {
|
||||
dp[0][j] = j;
|
||||
}
|
||||
// 状态转移:其余行列
|
||||
for (let i = 1; i <= n; i++) {
|
||||
for (let j = 1; j <= m; j++) {
|
||||
if (s.charAt(i - 1) === t.charAt(j - 1)) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[i][j] = dp[i - 1][j - 1];
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i][j] =
|
||||
Math.min(
|
||||
Math.min(dp[i][j - 1], dp[i - 1][j]),
|
||||
dp[i - 1][j - 1]
|
||||
) + 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[n][m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "TS"
|
||||
|
||||
```typescript title="edit_distance.ts"
|
||||
[class]{}-[func]{editDistanceDP}
|
||||
/* 编辑距离:动态规划 */
|
||||
function editDistanceDP(s: string, t: string): number {
|
||||
const n = s.length,
|
||||
m = t.length;
|
||||
const dp = Array.from({ length: n + 1 }, () =>
|
||||
Array.from({ length: m + 1 }, () => 0)
|
||||
);
|
||||
// 状态转移:首行首列
|
||||
for (let i = 1; i <= n; i++) {
|
||||
dp[i][0] = i;
|
||||
}
|
||||
for (let j = 1; j <= m; j++) {
|
||||
dp[0][j] = j;
|
||||
}
|
||||
// 状态转移:其余行列
|
||||
for (let i = 1; i <= n; i++) {
|
||||
for (let j = 1; j <= m; j++) {
|
||||
if (s.charAt(i - 1) === t.charAt(j - 1)) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[i][j] = dp[i - 1][j - 1];
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i][j] =
|
||||
Math.min(
|
||||
Math.min(dp[i][j - 1], dp[i - 1][j]),
|
||||
dp[i - 1][j - 1]
|
||||
) + 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[n][m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Dart"
|
||||
|
||||
```dart title="edit_distance.dart"
|
||||
[class]{}-[func]{editDistanceDP}
|
||||
/* 编辑距离:动态规划 */
|
||||
int editDistanceDP(String s, String t) {
|
||||
int n = s.length, m = t.length;
|
||||
List<List<int>> dp = List.generate(n + 1, (_) => List.filled(m + 1, 0));
|
||||
// 状态转移:首行首列
|
||||
for (int i = 1; i <= n; i++) {
|
||||
dp[i][0] = i;
|
||||
}
|
||||
for (int j = 1; j <= m; j++) {
|
||||
dp[0][j] = j;
|
||||
}
|
||||
// 状态转移:其余行列
|
||||
for (int i = 1; i <= n; i++) {
|
||||
for (int j = 1; j <= m; j++) {
|
||||
if (s[i - 1] == t[j - 1]) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[i][j] = dp[i - 1][j - 1];
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i][j] = min(min(dp[i][j - 1], dp[i - 1][j]), dp[i - 1][j - 1]) + 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[n][m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Rust"
|
||||
|
||||
```rust title="edit_distance.rs"
|
||||
[class]{}-[func]{edit_distance_dp}
|
||||
/* 编辑距离:动态规划 */
|
||||
fn edit_distance_dp(s: &str, t: &str) -> i32 {
|
||||
let (n, m) = (s.len(), t.len());
|
||||
let mut dp = vec![vec![0; m + 1]; n + 1];
|
||||
// 状态转移:首行首列
|
||||
for i in 1..= n {
|
||||
dp[i][0] = i as i32;
|
||||
}
|
||||
for j in 1..m {
|
||||
dp[0][j] = j as i32;
|
||||
}
|
||||
// 状态转移:其余行列
|
||||
for i in 1..=n {
|
||||
for j in 1..=m {
|
||||
if s.chars().nth(i - 1) == t.chars().nth(j - 1) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[i][j] = dp[i - 1][j - 1];
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i][j] = std::cmp::min(std::cmp::min(dp[i][j - 1], dp[i - 1][j]), dp[i - 1][j - 1]) + 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
dp[n][m]
|
||||
}
|
||||
```
|
||||
|
||||
=== "C"
|
||||
@@ -146,7 +397,32 @@ $$
|
||||
=== "Zig"
|
||||
|
||||
```zig title="edit_distance.zig"
|
||||
[class]{}-[func]{editDistanceDP}
|
||||
// 编辑距离:动态规划
|
||||
fn editDistanceDP(comptime s: []const u8, comptime t: []const u8) i32 {
|
||||
comptime var n = s.len;
|
||||
comptime var m = t.len;
|
||||
var dp = [_][m + 1]i32{[_]i32{0} ** (m + 1)} ** (n + 1);
|
||||
// 状态转移:首行首列
|
||||
for (1..n + 1) |i| {
|
||||
dp[i][0] = @intCast(i);
|
||||
}
|
||||
for (1..m + 1) |j| {
|
||||
dp[0][j] = @intCast(j);
|
||||
}
|
||||
// 状态转移:其余行列
|
||||
for (1..n + 1) |i| {
|
||||
for (1..m + 1) |j| {
|
||||
if (s[i - 1] == t[j - 1]) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[i][j] = dp[i - 1][j - 1];
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[i][j] = @min(@min(dp[i][j - 1], dp[i - 1][j]), dp[i - 1][j - 1]) + 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
return dp[n][m];
|
||||
}
|
||||
```
|
||||
|
||||
如图 14-30 所示,编辑距离问题的状态转移过程与背包问题非常类似,都可以看作是填写一个二维网格的过程。
|
||||
@@ -207,61 +483,330 @@ $$
|
||||
=== "Python"
|
||||
|
||||
```python title="edit_distance.py"
|
||||
[class]{}-[func]{edit_distance_dp_comp}
|
||||
def edit_distance_dp_comp(s: str, t: str) -> int:
|
||||
"""编辑距离:空间优化后的动态规划"""
|
||||
n, m = len(s), len(t)
|
||||
dp = [0] * (m + 1)
|
||||
# 状态转移:首行
|
||||
for j in range(1, m + 1):
|
||||
dp[j] = j
|
||||
# 状态转移:其余行
|
||||
for i in range(1, n + 1):
|
||||
# 状态转移:首列
|
||||
leftup = dp[0] # 暂存 dp[i-1, j-1]
|
||||
dp[0] += 1
|
||||
# 状态转移:其余列
|
||||
for j in range(1, m + 1):
|
||||
temp = dp[j]
|
||||
if s[i - 1] == t[j - 1]:
|
||||
# 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftup
|
||||
else:
|
||||
# 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = min(dp[j - 1], dp[j], leftup) + 1
|
||||
leftup = temp # 更新为下一轮的 dp[i-1, j-1]
|
||||
return dp[m]
|
||||
```
|
||||
|
||||
=== "C++"
|
||||
|
||||
```cpp title="edit_distance.cpp"
|
||||
[class]{}-[func]{editDistanceDPComp}
|
||||
/* 编辑距离:空间优化后的动态规划 */
|
||||
int editDistanceDPComp(string s, string t) {
|
||||
int n = s.length(), m = t.length();
|
||||
vector<int> dp(m + 1, 0);
|
||||
// 状态转移:首行
|
||||
for (int j = 1; j <= m; j++) {
|
||||
dp[j] = j;
|
||||
}
|
||||
// 状态转移:其余行
|
||||
for (int i = 1; i <= n; i++) {
|
||||
// 状态转移:首列
|
||||
int leftup = dp[0]; // 暂存 dp[i-1, j-1]
|
||||
dp[0] = i;
|
||||
// 状态转移:其余列
|
||||
for (int j = 1; j <= m; j++) {
|
||||
int temp = dp[j];
|
||||
if (s[i - 1] == t[j - 1]) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftup;
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = min(min(dp[j - 1], dp[j]), leftup) + 1;
|
||||
}
|
||||
leftup = temp; // 更新为下一轮的 dp[i-1, j-1]
|
||||
}
|
||||
}
|
||||
return dp[m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Java"
|
||||
|
||||
```java title="edit_distance.java"
|
||||
[class]{edit_distance}-[func]{editDistanceDPComp}
|
||||
/* 编辑距离:空间优化后的动态规划 */
|
||||
int editDistanceDPComp(String s, String t) {
|
||||
int n = s.length(), m = t.length();
|
||||
int[] dp = new int[m + 1];
|
||||
// 状态转移:首行
|
||||
for (int j = 1; j <= m; j++) {
|
||||
dp[j] = j;
|
||||
}
|
||||
// 状态转移:其余行
|
||||
for (int i = 1; i <= n; i++) {
|
||||
// 状态转移:首列
|
||||
int leftup = dp[0]; // 暂存 dp[i-1, j-1]
|
||||
dp[0] = i;
|
||||
// 状态转移:其余列
|
||||
for (int j = 1; j <= m; j++) {
|
||||
int temp = dp[j];
|
||||
if (s.charAt(i - 1) == t.charAt(j - 1)) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftup;
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = Math.min(Math.min(dp[j - 1], dp[j]), leftup) + 1;
|
||||
}
|
||||
leftup = temp; // 更新为下一轮的 dp[i-1, j-1]
|
||||
}
|
||||
}
|
||||
return dp[m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "C#"
|
||||
|
||||
```csharp title="edit_distance.cs"
|
||||
[class]{edit_distance}-[func]{editDistanceDPComp}
|
||||
/* 编辑距离:空间优化后的动态规划 */
|
||||
int editDistanceDPComp(string s, string t) {
|
||||
int n = s.Length, m = t.Length;
|
||||
int[] dp = new int[m + 1];
|
||||
// 状态转移:首行
|
||||
for (int j = 1; j <= m; j++) {
|
||||
dp[j] = j;
|
||||
}
|
||||
// 状态转移:其余行
|
||||
for (int i = 1; i <= n; i++) {
|
||||
// 状态转移:首列
|
||||
int leftup = dp[0]; // 暂存 dp[i-1, j-1]
|
||||
dp[0] = i;
|
||||
// 状态转移:其余列
|
||||
for (int j = 1; j <= m; j++) {
|
||||
int temp = dp[j];
|
||||
if (s[i - 1] == t[j - 1]) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftup;
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = Math.Min(Math.Min(dp[j - 1], dp[j]), leftup) + 1;
|
||||
}
|
||||
leftup = temp; // 更新为下一轮的 dp[i-1, j-1]
|
||||
}
|
||||
}
|
||||
return dp[m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Go"
|
||||
|
||||
```go title="edit_distance.go"
|
||||
[class]{}-[func]{editDistanceDPComp}
|
||||
/* 编辑距离:空间优化后的动态规划 */
|
||||
func editDistanceDPComp(s string, t string) int {
|
||||
n := len(s)
|
||||
m := len(t)
|
||||
dp := make([]int, m+1)
|
||||
// 状态转移:首行
|
||||
for j := 1; j <= m; j++ {
|
||||
dp[j] = j
|
||||
}
|
||||
// 状态转移:其余行
|
||||
for i := 1; i <= n; i++ {
|
||||
// 状态转移:首列
|
||||
leftUp := dp[0] // 暂存 dp[i-1, j-1]
|
||||
dp[0] = i
|
||||
// 状态转移:其余列
|
||||
for j := 1; j <= m; j++ {
|
||||
temp := dp[j]
|
||||
if s[i-1] == t[j-1] {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftUp
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = MinInt(MinInt(dp[j-1], dp[j]), leftUp) + 1
|
||||
}
|
||||
leftUp = temp // 更新为下一轮的 dp[i-1, j-1]
|
||||
}
|
||||
}
|
||||
return dp[m]
|
||||
}
|
||||
```
|
||||
|
||||
=== "Swift"
|
||||
|
||||
```swift title="edit_distance.swift"
|
||||
[class]{}-[func]{editDistanceDPComp}
|
||||
/* 编辑距离:空间优化后的动态规划 */
|
||||
func editDistanceDPComp(s: String, t: String) -> Int {
|
||||
let n = s.utf8CString.count
|
||||
let m = t.utf8CString.count
|
||||
var dp = Array(repeating: 0, count: m + 1)
|
||||
// 状态转移:首行
|
||||
for j in stride(from: 1, through: m, by: 1) {
|
||||
dp[j] = j
|
||||
}
|
||||
// 状态转移:其余行
|
||||
for i in stride(from: 1, through: n, by: 1) {
|
||||
// 状态转移:首列
|
||||
var leftup = dp[0] // 暂存 dp[i-1, j-1]
|
||||
dp[0] = i
|
||||
// 状态转移:其余列
|
||||
for j in stride(from: 1, through: m, by: 1) {
|
||||
let temp = dp[j]
|
||||
if s.utf8CString[i - 1] == t.utf8CString[j - 1] {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftup
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = min(min(dp[j - 1], dp[j]), leftup) + 1
|
||||
}
|
||||
leftup = temp // 更新为下一轮的 dp[i-1, j-1]
|
||||
}
|
||||
}
|
||||
return dp[m]
|
||||
}
|
||||
```
|
||||
|
||||
=== "JS"
|
||||
|
||||
```javascript title="edit_distance.js"
|
||||
[class]{}-[func]{editDistanceDPComp}
|
||||
/* 编辑距离:状态压缩后的动态规划 */
|
||||
function editDistanceDPComp(s, t) {
|
||||
const n = s.length,
|
||||
m = t.length;
|
||||
const dp = new Array(m + 1).fill(0);
|
||||
// 状态转移:首行
|
||||
for (let j = 1; j <= m; j++) {
|
||||
dp[j] = j;
|
||||
}
|
||||
// 状态转移:其余行
|
||||
for (let i = 1; i <= n; i++) {
|
||||
// 状态转移:首列
|
||||
let leftup = dp[0]; // 暂存 dp[i-1, j-1]
|
||||
dp[0] = i;
|
||||
// 状态转移:其余列
|
||||
for (let j = 1; j <= m; j++) {
|
||||
const temp = dp[j];
|
||||
if (s.charAt(i - 1) === t.charAt(j - 1)) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftup;
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = Math.min(Math.min(dp[j - 1], dp[j]), leftup) + 1;
|
||||
}
|
||||
leftup = temp; // 更新为下一轮的 dp[i-1, j-1]
|
||||
}
|
||||
}
|
||||
return dp[m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "TS"
|
||||
|
||||
```typescript title="edit_distance.ts"
|
||||
[class]{}-[func]{editDistanceDPComp}
|
||||
/* 编辑距离:状态压缩后的动态规划 */
|
||||
function editDistanceDPComp(s: string, t: string): number {
|
||||
const n = s.length,
|
||||
m = t.length;
|
||||
const dp = new Array(m + 1).fill(0);
|
||||
// 状态转移:首行
|
||||
for (let j = 1; j <= m; j++) {
|
||||
dp[j] = j;
|
||||
}
|
||||
// 状态转移:其余行
|
||||
for (let i = 1; i <= n; i++) {
|
||||
// 状态转移:首列
|
||||
let leftup = dp[0]; // 暂存 dp[i-1, j-1]
|
||||
dp[0] = i;
|
||||
// 状态转移:其余列
|
||||
for (let j = 1; j <= m; j++) {
|
||||
const temp = dp[j];
|
||||
if (s.charAt(i - 1) === t.charAt(j - 1)) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftup;
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = Math.min(Math.min(dp[j - 1], dp[j]), leftup) + 1;
|
||||
}
|
||||
leftup = temp; // 更新为下一轮的 dp[i-1, j-1]
|
||||
}
|
||||
}
|
||||
return dp[m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Dart"
|
||||
|
||||
```dart title="edit_distance.dart"
|
||||
[class]{}-[func]{editDistanceDPComp}
|
||||
/* 编辑距离:空间优化后的动态规划 */
|
||||
int editDistanceDPComp(String s, String t) {
|
||||
int n = s.length, m = t.length;
|
||||
List<int> dp = List.filled(m + 1, 0);
|
||||
// 状态转移:首行
|
||||
for (int j = 1; j <= m; j++) {
|
||||
dp[j] = j;
|
||||
}
|
||||
// 状态转移:其余行
|
||||
for (int i = 1; i <= n; i++) {
|
||||
// 状态转移:首列
|
||||
int leftup = dp[0]; // 暂存 dp[i-1, j-1]
|
||||
dp[0] = i;
|
||||
// 状态转移:其余列
|
||||
for (int j = 1; j <= m; j++) {
|
||||
int temp = dp[j];
|
||||
if (s[i - 1] == t[j - 1]) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftup;
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = min(min(dp[j - 1], dp[j]), leftup) + 1;
|
||||
}
|
||||
leftup = temp; // 更新为下一轮的 dp[i-1, j-1]
|
||||
}
|
||||
}
|
||||
return dp[m];
|
||||
}
|
||||
```
|
||||
|
||||
=== "Rust"
|
||||
|
||||
```rust title="edit_distance.rs"
|
||||
[class]{}-[func]{edit_distance_dp_comp}
|
||||
/* 编辑距离:空间优化后的动态规划 */
|
||||
fn edit_distance_dp_comp(s: &str, t: &str) -> i32 {
|
||||
let (n, m) = (s.len(), t.len());
|
||||
let mut dp = vec![0; m + 1];
|
||||
// 状态转移:首行
|
||||
for j in 1..m {
|
||||
dp[j] = j as i32;
|
||||
}
|
||||
// 状态转移:其余行
|
||||
for i in 1..=n {
|
||||
// 状态转移:首列
|
||||
let mut leftup = dp[0]; // 暂存 dp[i-1, j-1]
|
||||
dp[0] = i as i32;
|
||||
// 状态转移:其余列
|
||||
for j in 1..=m {
|
||||
let temp = dp[j];
|
||||
if s.chars().nth(i - 1) == t.chars().nth(j - 1) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftup;
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = std::cmp::min(std::cmp::min(dp[j - 1], dp[j]), leftup) + 1;
|
||||
}
|
||||
leftup = temp; // 更新为下一轮的 dp[i-1, j-1]
|
||||
}
|
||||
}
|
||||
dp[m]
|
||||
}
|
||||
```
|
||||
|
||||
=== "C"
|
||||
@@ -273,5 +818,33 @@ $$
|
||||
=== "Zig"
|
||||
|
||||
```zig title="edit_distance.zig"
|
||||
[class]{}-[func]{editDistanceDPComp}
|
||||
// 编辑距离:空间优化后的动态规划
|
||||
fn editDistanceDPComp(comptime s: []const u8, comptime t: []const u8) i32 {
|
||||
comptime var n = s.len;
|
||||
comptime var m = t.len;
|
||||
var dp = [_]i32{0} ** (m + 1);
|
||||
// 状态转移:首行
|
||||
for (1..m + 1) |j| {
|
||||
dp[j] = @intCast(j);
|
||||
}
|
||||
// 状态转移:其余行
|
||||
for (1..n + 1) |i| {
|
||||
// 状态转移:首列
|
||||
var leftup = dp[0]; // 暂存 dp[i-1, j-1]
|
||||
dp[0] = @intCast(i);
|
||||
// 状态转移:其余列
|
||||
for (1..m + 1) |j| {
|
||||
var temp = dp[j];
|
||||
if (s[i - 1] == t[j - 1]) {
|
||||
// 若两字符相等,则直接跳过此两字符
|
||||
dp[j] = leftup;
|
||||
} else {
|
||||
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
|
||||
dp[j] = @min(@min(dp[j - 1], dp[j]), leftup) + 1;
|
||||
}
|
||||
leftup = temp; // 更新为下一轮的 dp[i-1, j-1]
|
||||
}
|
||||
}
|
||||
return dp[m];
|
||||
}
|
||||
```
|
||||
|
||||
File diff suppressed because it is too large
Load Diff
File diff suppressed because it is too large
Load Diff
File diff suppressed because it is too large
Load Diff
Reference in New Issue
Block a user