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krahets
2023-11-17 00:35:19 +08:00
parent c7794e1a84
commit 5ae2d5e925
17 changed files with 229 additions and 178 deletions
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25
docs/chapter_dynamic_programming/dp_problem_features.md
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@@ -264,15 +264,18 @@ $$
if (n == 1 || n == 2)
return cost[n];
// 初始化 dp 表，用于存储子问题的解
int dp[n + 1];
int *dp = calloc(n + 1, sizeof(int));
// 初始状态：预设最小子问题的解
dp[1] = cost[1];
dp[2] = cost[2];
// 状态转移：从较小子问题逐步求解较大子问题
for (int i = 3; i <= n; i++) {
dp[i] = min(dp[i - 1], dp[i - 2]) + cost[i];
dp[i] = myMin(dp[i - 1], dp[i - 2]) + cost[i];
}
return dp[n];
int res = dp[n];
// 释放内存
free(dp);
return res;
}
```
@@ -503,7 +506,7 @@ $$
int a = cost[1], b = cost[2];
for (int i = 3; i <= n; i++) {
int tmp = b;
b = min(a, tmp) + cost[i];
b = myMin(a, tmp) + cost[i];
a = tmp;
}
return b;
@@ -815,8 +818,10 @@ $$
return 1;
}
// 初始化 dp 表，用于存储子问题的解
int dp[n + 1][3];
memset(dp, 0, sizeof(dp));
int **dp = malloc((n + 1) * sizeof(int *));
for (int i = 0; i <= n; i++) {
dp[i] = calloc(3, sizeof(int));
}
// 初始状态：预设最小子问题的解
dp[1][1] = 1;
dp[1][2] = 0;
@@ -827,7 +832,13 @@ $$
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];
int res = dp[n][1] + dp[n][2];
// 释放内存
for (int i = 0; i <= n; i++) {
free(dp[i]);
}
free(dp);
return res;
}
```