HDU 1114 Piggy-Bank

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define inf 0x3f3f3f3f
int t,e,f,n;
int v[505],w[505],dp[10010];//当前容量小能选择的最小的价值。
int main()
{
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d%d",&e,&f);
        int d=f-e;
        scanf("%d",&n);
        for(int i=0; i<n; i++)
            scanf("%d%d",&v[i],&w[i]);
        for(int i=0; i<=d; i++)
            dp[i]=inf;
        dp[0]=0;
        for(int i=0; i<n; i++)
        {
            for(int j=w[i]; j<=d; j++)
            {
                dp[j]=min(dp[j],dp[j-w[i]]+v[i]);
            }
        }
        if(dp[d]==inf)
            printf("This is impossible.\n");
        else
            printf("The minimum amount of money in the piggy-bank is %d.\n",dp[d]);
    }
    return 0;
}