HDU1114 PiggyBank(完全背包,dp)

题目链接。

分析：

该题的状态转移方程为：

f[v]=min{f[v],f[v-w[i]]+p[i]}，将所有值初始化为无穷大

AC代码如下：

#include <stdio.h>

#define MAXN 10010

const int INF = (1<<25);

int dp[MAXN];

int main(){
    int T, vol, vol1, vol2, n, i, w[550], p[550], j;

    scanf("%d", &T);
    while(T--){
        scanf("%d %d", &vol1, &vol2);
        vol = vol2-vol1;

        scanf("%d", &n);

        for(i=0; i<n; i++) scanf("%d %d", &p[i], &w[i]);
        for(i=0; i<=vol; i++) dp[i] = INF;

        dp[0] = 0;

        for(i=0; i<n; i++){
            for(j=w[i]; j<=vol; j++){
                if(dp[j] > dp[j-w[i]]+p[i]) dp[j] = dp[j-w[i]]+p[i];
            }
        }

        if(dp[vol] != INF) printf("The minimum amount of money in the piggy-bank is %d.\n", dp[vol]);
        else printf("This is impossible.\n");
    }

    return 0;
}