先用第一个量覆盖整个数组再min

#include<bits/stdc++.h>
using namespace std;
int dp[1000005];
int m,n,w[1000005],v[1000005];
int main(){
	cin>>n>>m;
    m-=n;
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>v[i]>>w[i];
    }
    for(int j=w[1];j<=m;j++){
        dp[j]=max(dp[j],dp[j-w[1]]+v[1]);
    }//覆盖
    for(int i=2;i<=n;i++){//注意i=2
        for(int j=w[i];j<=m;j++){
            dp[j]=min(dp[j],dp[j-w[i]]+v[i]);
        }
    }//正常完全背包模板
    if(dp[m]==0){
        cout<<"This is impossible.";
    }
    else{
        cout<<"The minimum amount of money in the piggy-bank is "<<dp[m]<<".";
    }
	return 0;
}