30分三维背包求助

#include<iostream>
#include<cstdio>
#include<cstdlib>
using namespace std;

int weight,mass;
int foodnum;
int foodw[55]={0},foodm[55]={0},foodca[55]={0};
int f[55][510][510]={0};

int main()
{
    cin>>weight>>mass>>foodnum;
    for(int i=1;i<=foodnum;i++)
        cin>>foodw[i]>>foodm[i]>>foodca[i];
    for(int i=1;i<=foodnum;i++)
        for(int w=foodw[i];w<=weight;w++)
            for(int m=foodm[i];m<=mass;m++)
                f[i][w][m]=max(f[i-1][w][m],f[i-1][w-foodw[i]][m-foodm[i]]+foodca[i]);
    cout<<f[foodnum][weight][mass];
    return 0;
}