蛇形矩形(HJ35)

#include <iostream>

using namespace std;

int main()
{
    int k = 0;
    int N = 0;
    int num = 0;

    while (cin >> k)
    {
        num = 1;

        for (int i = 0; i < N; i++)
        {
            num += i;
            k = num;
            for (int j = 0; j < N - i; j++)
            {
                cout << k;
                if (j != N - 1 - i)
                    cout << " ";
                else
                    cout << endl;
                k += i + 2 + j;
            }
        }
    }

    return 0;
}