洛谷P1060-开心的金明(背包问题）

#include<iostream>
#include<algorithm>
using namespace std;
int weight[30],cost[30],f[10000];
int money,number;
int main(){

    cin >> money >> number;
    for(int i = 1;i <= number;i++){
        cin >>cost[i] >>weight[i];
        weight[i] *= cost[i];
    }

    for(int i = 1;i <= number;i++)
        for(int j = money;j >= cost[i];j--)
            f[j] = max(f[j],f[j - cost[i]] + weight[i]);
    cout << f[money] <<endl;
    return 0;
}