Piggy-Bank HDU

#include<iostream>
#include<cstring>
using namespace std;
const int INF=0x3f3f3f3f;
int t,e,f,n,dp[10010];
struct node {
    int p, w; //价值   重量
} no[10000];
int main() {
    cin >> t;
    while(t--) {
        memset(dp,0x3f,sizeof dp);
        //e是空存钱罐的重量，f是满存钱罐的重量，n是钱的种数。
        cin>>e>>f>>n; 
        for(int i = 0; i < n; i++) 
            cin>>no[i].p>>no[i].w;
        dp[0]=0;
        for(int i=0;i<n;i++) 
            for(int j=no[i].w;j<=f-e;j++) 
                dp[j]=min(dp[j],dp[j-no[i].w]+no[i].p);
        if(dp[f - e]!=INF)
            cout << "The minimum amount of money in the piggy-bank is " << dp[f - e] << "." << endl;
        else
            cout << "This is impossible." << endl;
    }
    return 0;
}