In tam giác số

#include <iostream>

/* MinGW build EXE
G++ TamGiacSo.cpp -o TamGiacSo.exe && TamGiacSo.exe
*/

using namespace std;

int main(int, const char * [])
{
    int N = 0;

    cout << "Enter a number (0-9): "; cin >> N;

    for(int i = 1; i <= N; i++) {
        cout << '\n';
        for(int j = 1; j <= N - i; j++) cout << '\x20';
        for(int k = 1; k <= i; k++) cout << k;
        for(int l = i - 1; l >= 1; l--) cout << l;
    }
}