hello-algo/codes/c/chapter_dynamic_programming/coin_change_ii.c
Yudong Jin f7c41b6bef
fix: Update C code for compatibility with the MSVC compiler (#949)
* Replace VLA with malloc
Replace VLA with malloc to make C code
compatible with cl compiler on Windows.

* Fix C code for CI compiler.

* Fix C code compability to CI.

* check the trigger
2023-11-17 00:29:54 +08:00

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/**
* File: coin_change_ii.c
* Created Time: 2023-10-02
* Author: Zuoxun (845242523@qq.com)
*/
#include "../utils/common.h"
/* 零钱兑换 II动态规划 */
int coinChangeIIDP(int coins[], int amt, int coinsSize) {
int n = coinsSize;
// 初始化 dp 表
int **dp = malloc((n + 1) * sizeof(int *));
for (int i = 0; i <= n; i++) {
dp[i] = calloc(amt + 1, sizeof(int));
}
// 初始化首列
for (int i = 0; i <= n; i++) {
dp[i][0] = 1;
}
// 状态转移
for (int i = 1; i <= n; i++) {
for (int a = 1; a <= amt; a++) {
if (coins[i - 1] > a) {
// 若超过目标金额,则不选硬币 i
dp[i][a] = dp[i - 1][a];
} else {
// 不选和选硬币 i 这两种方案之和
dp[i][a] = dp[i - 1][a] + dp[i][a - coins[i - 1]];
}
}
}
int res = dp[n][amt];
// 释放内存
for (int i = 0; i <= n; i++) {
free(dp[i]);
}
free(dp);
return res;
}
/* 零钱兑换 II空间优化后的动态规划 */
int coinChangeIIDPComp(int coins[], int amt, int coinsSize) {
int n = coinsSize;
// 初始化 dp 表
int *dp = calloc(amt + 1, sizeof(int));
dp[0] = 1;
// 状态转移
for (int i = 1; i <= n; i++) {
for (int a = 1; a <= amt; a++) {
if (coins[i - 1] > a) {
// 若超过目标金额,则不选硬币 i
dp[a] = dp[a];
} else {
// 不选和选硬币 i 这两种方案之和
dp[a] = dp[a] + dp[a - coins[i - 1]];
}
}
}
int res = dp[amt];
// 释放内存
free(dp);
return res;
}
/* Driver code */
int main() {
int coins[] = {1, 2, 5};
int coinsSize = sizeof(coins) / sizeof(coins[0]);
int amt = 5;
// 动态规划
int res = coinChangeIIDP(coins, amt, coinsSize);
printf("凑出目标金额的硬币组合数量为 %d\n", res);
// 空间优化后的动态规划
res = coinChangeIIDPComp(coins, amt, coinsSize);
printf("凑出目标金额的硬币组合数量为 %d\n", res);
return 0;
}