RE求助

#include<iostream>
using namespace std;

void swap_a(int a[100][4], int i, int j)
{
    int t = 0;
    for (int count = 0; count < 4; count++)
    {
        t = a[i][count];
        a[i][count] = a[j][count];
        a[j][count] = t;
    }
    return;
}

int sum(int a[100][4], int i)
{
    int sum = 0;
    for (int j = 0; j < 3; j++)
    {
        sum += a[i][j];
    }
    return sum;
}

void ord_a(int a[100][4], int n)
{
    int sum1, sum2;
    for (int i = 0; i < n; i++)
    {
        sum1 = sum(a, i);
        for (int j = i + 1; j < n; j++)
        {
            sum2 = sum(a, j);
            if (sum2 == sum1)
            {
                if (a[i][3] > a[j][3])
                {
                    swap_a(a, i, j);
                }
            }
            if (sum2 > sum1)
            {
                swap_a(a, i, j);
                sum1 = sum2;
            }
        }
    }
    return;
}

int main()
{
    int n;
    while (cin >> n)
    {
        int a[100][4];
        for (int i = 0; i < n; i++)
        {
            for (int j = 0; j < 3; j++)
            {
                cin >> a[i][j];
            }
            a[i][3] = i + 1;
        }
        ord_a(a, n);
        for (int i = 0; i < n; i++)
        {
            cout << a[i][3] << " " << sum(a, i) << endl;
            if (i == 4)
            {
                break;
            }
        }
    }
    return 0;
}