Dev - C++ - Programar una estructura de control de ciclos en C++

#include <iostream>

using namespace std;

int main()

{

    int n;

    cout << "\nNumero: "; cin >> n;

    int k = 1;

    while (k <= n)

    {

        for (int i = 1; i <= k; i++)

            cout << i << " ";

        cout << endl;

        k++;

    }

    k = n - 1;

    while (k >= 1)

    {

        for (int i = 1; i <= k; i++)

            cout << i << " ";

        cout << endl;

        k--;

    }

    return 0;

}