01. Number Pyramid

#include <iostream>

using namespace std;

int main() {

    int num;
    cin >> num;

    int counter = 1;

    for (int row = 1; row <= num; row++) {
        for (int col = 0; col < row; col++) {
            if (counter > num) {
                break;
            }
            cout << counter << " ";
            counter++;
        }
        if (counter > num) {
            break;
        }
        cout << endl;
    }

    return 0;
}

Или:

#include <iostream>

using namespace std;

int main() {

    int num;
    cin >> num;

    int counter = 1;

    for (int row = 1; row <= num || counter <= num; row++) {
        for (int col = 0; col < row && counter <= num; col++) {
            cout << counter << " ";
            counter++;
        }
        cout << endl;
    }

    return 0;
}