Integer Triangle covered with 1

// cpp program: integer triangle covered with 1.
// created on April, 2016
// Author: fueanta

#include <iostream>
using namespace std;

int main(void) {
    int num=0,cnt=0;
    cin >> num;
    for (int i=0;i<num;i++) { cnt++; int val=1;
        if (num==cnt) {
            for (int j=0;j<(2*cnt)-1;j++) {
                cout << val;
            }
            break;
        }
        for (int j=0;j<num-cnt;j++) {
            cout << " ";
        }
        for (int j=0;j<cnt;j++) {
            cout << val;
            val++;
        } val--;
        for (int j=0;j<cnt-1;j++) {
            cout << --val;
        }
        cout << endl;
    }
    return 0;
}