0分！求助！

#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <algorithm>
using namespace std;
struct node
{
	int c,m,e,a;
}stu[1005];
int n,sum;
int main()
{
	cin >> n;
	for(int i=1;i<=n;i++)
	{
		cin >> stu[i].c >> stu[i].m >> stu[i].e;
		stu[i].a=stu[i].c+stu[i].m+stu[i].e;
	}
	for(int i=1;i<=n;i++)
	{
	    for(int j=i+1;j<=n;j++)
	    {
	        if((abs(stu[i].c-stu[j].c<=5)) && (abs(stu[i].m-stu[j].m<=5)) && 
	        (abs(stu[i].e-stu[j].e<=5)) && (abs(stu[i].a-stu[j].a<=10)))
	        {
	            sum++;
	        }
	    }
	}
	cout << sum;
	return 0;
}