title: Triangular Numbers 1
signature: function triangularNumbers1(num: number): boolean {
test_code: 
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  function convertToString(value: any): string{
      return JSON.stringify(value, function (key, val) {
          if (val instanceof Set) {
              return Array.from(val);
          } return val;});
  }
  
  function validateSolution(actual: boolean, expected: boolean): boolean {
      return convertToString(actual) === convertToString(expected);
  }
  
  function driver(num: number, expected:boolean): string {
      try{
          if (validateSolution(PLACEHOLDER_FN_NAME(num),expected)){
              return "PASSED";
          }
          return "FAILED";
      } catch (error) {
        return error.name;
      }
      
  }
      
  function main(){
    let result = '';
    result = driver(1, true);
    console.log(`TEST-0...${result}`);
  
    result = driver(3, true);
    console.log(`TEST-1...${result}`);
  
    result = driver(6, true);
    console.log(`TEST-2...${result}`);
  
    result = driver(10, true);
    console.log(`TEST-3...${result}`);
  
    result = driver(55, true);
    console.log(`TEST-4...${result}`);
  
    result = driver(48, false);
    console.log(`TEST-5...${result}`);
  
    result = driver(63, false);
    console.log(`TEST-6...${result}`);
  
    result = driver(72, false);
    console.log(`TEST-7...${result}`);
  
    result = driver(16, false);
    console.log(`TEST-8...${result}`);
  
    result = driver(85, false);
    console.log(`TEST-9...${result}`);
  
  };
  
  main();
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;
  }