This commit is contained in:
krahets
2023-10-09 05:05:19 +08:00
parent 2f761d9865
commit ec3f58fb70
7 changed files with 144 additions and 25 deletions

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@ -809,7 +809,26 @@ $$
=== "C"
```c title="climbing_stairs_constraint_dp.c"
[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
int dp[n + 1][3];
memset(dp, 0, sizeof(dp));
// 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];
}
```
=== "Zig"

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@ -391,7 +391,31 @@ $$
=== "C"
```c title="edit_distance.c"
[class]{}-[func]{editDistanceDP}
/* 编辑距离:动态规划 */
int editDistanceDP(char *s, char *t, int n, int m) {
int dp[n + 1][m + 1];
memset(dp, 0, sizeof(dp));
// 状态转移:首行首列
for (int i = 1; i <= n; i++) {
dp[i][0] = i;
}
for (int j = 1; j <= m; j++) {
dp[0][j] = j;
}
// 状态转移:其余行列
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= m; j++) {
if (s[i - 1] == t[j - 1]) {
// 若两字符相等,则直接跳过此两字符
dp[i][j] = dp[i - 1][j - 1];
} else {
// 最少编辑步数 = 插入、删除、替换这三种操作的最少编辑步数 + 1
dp[i][j] = min(min(dp[i][j - 1], dp[i - 1][j]), dp[i - 1][j - 1]) + 1;
}
}
}
return dp[n][m];
}
```
=== "Zig"
@ -812,7 +836,34 @@ $$
=== "C"
```c title="edit_distance.c"
[class]{}-[func]{editDistanceDPComp}
/* 编辑距离:空间优化后的动态规划 */
int editDistanceDPComp(char *s, char *t, int n, int m) {
int dp[m + 1];
memset(dp, 0, sizeof(dp));
// 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];
}
```
=== "Zig"