spoj 39

DP  完全背包问题 的   d[i] = min(d[i], d[i-w]+p)   d[i]表示当总重量为i时可装的最小价值

#include <cstdio>
#include <cstring>
#include <algorithm>
#define INF 100000000

using namespace std;

int d[10010];
int main()
{
    int t,n,m,wei;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%d%d",&n,&m), wei = m-n;
        for(int i = 0; i <= wei; i++) d[i] = INF;
        d[0] = 0;
        scanf("%d",&m);
        for(int q = 0; q < m; q++)
        {
            int W,P;
            scanf("%d%d",&P,&W);
            for(int j = W; j <= wei; j++)
                d[j] = min(d[j], d[j-W]+P);
        }
        if(d[wei] != INF)
            printf("The minimum amount of money in the piggy-bank is %d.\n",d[wei]);
        else
            puts("This is impossible.");
    }
}