SPOJ Problem 77:Piggy-Bank

#include<cstdio>
#include<cstring>
#define INF 1000000005
int ew,fw,n,i,j,t,m;
int v[505],w[505],f[10005];
int min(int a,int b){return a<b?a:b;}
int main(){
    scanf("%d",&t);
    while(t--){
        scanf("%d%d",&ew,&fw);
        scanf("%d",&n);
        for (i=1;i<=n;i++)
            scanf("%d%d",&v[i],&w[i]);
        for (i=1;i<=fw-ew;i++)
            f[i]=INF;
        f[0]=0;
        for (i=1;i<=n;i++)
            for (j=w[i];j<=fw-ew;j++)
                f[j]=min(f[j],f[j-w[i]]+v[i]);
        if (f[fw-ew]==INF)printf("This is impossible.\n");
        else printf("The minimum amount of money in the piggy-bank is %d.\n",f[fw-ew]);
    }
}