一道C++题目

#include <iostream>
using namespace std;

int main()
{
    int length;
    cout << "样本输入:"<<endl; 
    cin >> length;
    cout << "样本输出:"<<endl; 
    for (int i = 1; i <= length; i++) 
    {
        for (int j = 1; j <= length; j++) 
        {
             cout << " ("<<i<<","<<j<<") ";
             if (j == length) 
             {
                 cout << "\n";    
             }
        }
    }
    return 0;
}