比比成绩

本题代码不难，可是运行完发现老是错误，最主要的是忘了给加一个绝对值

#include <iostream>
#include <cmath>
using namespace std;
int main()
{
    int a[1000][4] = { 0 }, N, i, j, count = 0;
    int sum[1000] = { 0 };
    cin >> N;
    for (i = 1; i <= N; i++)
    {
        for (j = 1; j <= 3; j++)
        {
            cin >> a[i][j];
        }
    }
    for (i = 1; i <=N; i++)
    {
        for (j = 1; j <= 3; j++)
        {
            sum[i] += a[i][j];

        }
    }
    for (i = 1; i <= N; i++)
    {
       

            if ((abs(a[i + 1][1] - a[i][1]) <= 5) && (abs(a[i + 1][2] - a[i][2] )<= 5) && (abs(a[i + 1][3] - a[i][3]) <= 5) && (abs(sum[i + 1] - sum[i]) <= 10))
                count++;
   
    }
    cout << count;
    return 0;
}