RE,求助！

#include<iostream>
#include<stdio.h>
#include<math.h>
using namespace std;
int main() {
	int n = 0, a[1100][5] = { 0 }, b[1010] = { 0 };
	int cnt = 0;
	scanf("%d", &n);
	for (int i = 1; i <= n; i++){
		cin >> a[i][1] >> a[i][2] >> a[i][3];
		b[i] = a[i][1] + a[i][2] + a[i][3];
	}
	for (int i = 1; i <= n - 1; i++) {
		for (int j = i + 1; i <= n;j++) {
			if (abs(a[i][1] - a[j][1]) <= 5 &&
				abs(a[i][2] - a[j][2]) <= 5 &&
				abs(a[i][3] - a[j][3]) <= 5 &&
				abs(b[i] - b[j]) <= 10)
				cnt++;
		}
	}
    cout <<cnt << endl;
	return 0;
}