title: Triangular Numbers 1
signature: pub fn triangular_numbers_1(num: i32) -> bool {
test_code: use std::collections::HashMap;
  use std::collections::HashSet;
  use std::cmp::*;
  use std::collections::*;
  use std::fmt::*; 
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  pub fn validate_solution(actual: bool, expected: bool)->bool{
  return actual==expected
  }
  pub fn driver(num: i32, expected: bool)->String{
      if validate_solution(PLACEHOLDER_FN_NAME(num), expected) {
        return "PASSED".to_string();
      };
      return "FAILED".to_string();
  
  }
  
  fn main() {
      println!("TEST-0...{}", driver(
        1, 
        true
      ));
      
      println!("TEST-1...{}", driver(
        3, 
        true
      ));
      
      println!("TEST-2...{}", driver(
        6, 
        true
      ));
      
      println!("TEST-3...{}", driver(
        10, 
        true
      ));
      
      println!("TEST-4...{}", driver(
        55, 
        true
      ));
      
      println!("TEST-5...{}", driver(
        48, 
        false
      ));
      
      println!("TEST-6...{}", driver(
        63, 
        false
      ));
      
      println!("TEST-7...{}", driver(
        72, 
        false
      ));
      
      println!("TEST-8...{}", driver(
        16, 
        false
      ));
      
      println!("TEST-9...{}", driver(
        85, 
        false
      ));
      
  }
source_py: def triangular_numbers_1(num):
      if (num < 0):
          return False
      c = ((- 2) * num)
      (b, a) = (1, 1)
      d = ((b * b) - ((4 * a) * c))
      if (d < 0):
          return False
      root1 = (((- b) + math.sqrt(d)) / (2 * a))
      root2 = (((- b) - math.sqrt(d)) / (2 * a))
      if ((root1 > 0) and (math.floor(root1) == root1)):
          return True
      if ((root2 > 0) and (math.floor(root2) == root2)):
          return True
      return False
source_cpp: bool triangular_numbers_1(int num) {
    if ( num < 0 ) return false;
    int c = ( - 2 * num );
    int b = 1, a = 1;
    int d = ( b * b ) - ( 4 * a * c );
    if ( d < 0 ) return false;
    float root1 = ( - b + sqrt ( d ) ) / ( 2 * a );
    float root2 = ( - b - sqrt ( d ) ) / ( 2 * a );
    if ( root1 > 0 && floor ( root1 ) == root1 ) return true;
    if ( root2 > 0 && floor ( root2 ) == root2 ) return true;
    return false;
  }