求助简单01背包

#include<bits/stdc++.h>
using namespace std;
int dp[500010], n, V, w[500010], v[500010];
int main(){
    cin >> V >> n;
    for(int i = 1;i <= n;i++){
        cin >> v[i] >> w[i];
        w[i] = v[i] * w[i];
    }
    for(int i = 1;i <= n;i++){
        for(int j = V;j >= v[i];j--){
            dp[j] = max(dp[j - 1],dp[j - v[i]] + w[i]);
        }
    }
    cout << dp[V];
}