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krahets
2023-02-08 20:30:14 +08:00
parent 7156a5f832
commit 30ed83e5b1
10 changed files with 130 additions and 49 deletions
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chapter_sorting/quick_sort.md
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@@ -141,14 +141,14 @@ comments: true
```javascript title="quick_sort.js"
/* 元素交换 */
function swap(nums, i, j) {
swap(nums, i, j) {
let tmp = nums[i];
nums[i] = nums[j];
nums[j] = tmp;
}
/* 哨兵划分 */
function partition(nums, left, right) {
partition(nums, left, right) {
// 以 nums[left] 作为基准数
let i = left, j = right;
while (i < j) {
@@ -159,9 +159,9 @@ comments: true
i += 1; // 从左向右找首个大于基准数的元素
}
// 元素交换
swap(nums, i, j); // 交换这两个元素
this.swap(nums, i, j); // 交换这两个元素
}
swap(nums, i, left); // 将基准数交换至两子数组的分界线
this.swap(nums, i, left); // 将基准数交换至两子数组的分界线
return i; // 返回基准数的索引
}
```
@@ -170,14 +170,14 @@ comments: true
```typescript title="quick_sort.ts"
/* 元素交换 */
function swap(nums: number[], i: number, j: number): void {
swap(nums: number[], i: number, j: number): void {
let tmp = nums[i];
nums[i] = nums[j];
nums[j] = tmp;
}
/* 哨兵划分 */
function partition(nums: number[], left: number, right: number): number {
partition(nums: number[], left: number, right: number): number {
// 以 nums[left] 作为基准数
let i = left, j = right;
while (i < j) {
@@ -188,9 +188,9 @@ comments: true
i += 1; // 从左向右找首个大于基准数的元素
}
// 元素交换
swap(nums, i, j); // 交换这两个元素
this.swap(nums, i, j); // 交换这两个元素
}
swap(nums, i, left); // 将基准数交换至两子数组的分界线
this.swap(nums, i, left); // 将基准数交换至两子数组的分界线
return i; // 返回基准数的索引
}
```
@@ -698,13 +698,12 @@ comments: true
}
/* 哨兵划分（三数取中值） */
func partition(nums: inout [Int], left: Int, right: Int) -> Int {
func partitionMedian(nums: inout [Int], left: Int, right: Int) -> Int {
// 选取三个候选元素的中位数
let med = medianThree(nums: nums, left: left, mid: (left + right) / 2, right: right)
// 将中位数交换至数组最左端
swap(nums: &nums, i: left, j: med)
// 以 nums[left] 作为基准数
// 下同省略...
return partition(nums: &nums, left: left, right: right)
}
```
@@ -879,7 +878,7 @@ comments: true
```swift title="quick_sort.swift"
/* 快速排序（尾递归优化） */
func quickSort(nums: inout [Int], left: Int, right: Int) {
func quickSortTailCall(nums: inout [Int], left: Int, right: Int) {
var left = left
var right = right
// 子数组长度为 1 时终止
@@ -888,10 +887,10 @@ comments: true
let pivot = partition(nums: &nums, left: left, right: right)
// 对两个子数组中较短的那个执行快排
if (pivot - left) < (right - pivot) {
quickSort(nums: &nums, left: left, right: pivot - 1) // 递归排序左子数组
quickSortTailCall(nums: &nums, left: left, right: pivot - 1) // 递归排序左子数组
left = pivot + 1 // 剩余待排序区间为 [pivot + 1, right]
} else {
quickSort(nums: &nums, left: pivot + 1, right: right) // 递归排序右子数组
quickSortTailCall(nums: &nums, left: pivot + 1, right: right) // 递归排序右子数组
right = pivot - 1 // 剩余待排序区间为 [left, pivot - 1]
}
}