_fur | C++ Aditya Bayu

#include <iostream>

using namespace std;

int main(void)
{
        // Deklarasi variable
        unsigned int line, n, i, j, totalLine, temp;
        unsigned int pos = 0;

        // Jumlah input
        cin >> n;
        if (n > 26) return 22;

        // Menentukan jumlah baris
        for (totalLine = 1, temp = 1; temp < n; temp += ++totalLine);

        for (line = 1; line <= totalLine; line++) {
                // Tulis spasi
                for (i = 0; i < (totalLine - line); i++)
                        cout << " ";

                // Tulis karakter
                for (j = 0; j < line && pos < n; j++)
                        cout << static_cast<char>('A' + pos++) << " ";

                // Akhiri baris
                cout << endl;
        }

        return 0;
}