#include <iostream>
#include <iomanip>
#include <string>
 
int main(int argc, char *argv[]) {
  int iNum = 20; // ideone does not insert the CRLF chars - output is not beautiful
//  std::cout << "Number: ";
//  std::cin >> iNum;
 
  std::cout << iNum << " triangular number = " << (iNum * (iNum + 1) / 2) << std::endl;
 
  for (int a = 1; a <= iNum; a++) {
    std::cout << std::setw((iNum + 2) - a);
    for (int d = 1; d <= a; d++) {
      std::cout << "o ";
    }
    std::cout << std::endl;
  }
 
  return 0;
}
 

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

MjAK

20