poj 1384 Piggy-Bank

#include <iostream>        //dp
using namespace std;
#define  MAX 999999
int dp[10000],weight[510],value[510];
int main()
{
    int t,e,f,n;
    int i,j,total,min_w;
    scanf("%d",&t);
    while (t--)
    {
        scanf("%d%d%d",&e,&f,&n);
        total=f-e;
        min_w=MAX;
        for(i=0;i<n;i++)
        {
            scanf("%d%d",&value[i],&weight[i]);
            if(min_w>weight[i])
                min_w=weight[i];
        }
        for(i=1;i<=total;i++)
            dp[i]=MAX;
        dp[0]=0;
        for (i=min_w;i<=total;i++)        //从1开始也可以AC
        {
            for(j=0;j<n;j++)
                if(weight[j]<=i && dp[i]>dp[i-weight[j]]+value[j])        //dp[a]=b,表示重量为a,花费最小为b
                {
                    dp[i]=dp[i-weight[j]]+value[j];
                }
        }
        if(dp[total]==MAX)
            printf("This is impossible.\n");
        else
            printf("The minimum amount of money in the piggy-bank is %d.\n", dp[total]);
    }
    return 0;
}