title: Triangular Numbers 1
signature: class Solution {
  
      public bool TriangularNumbers1(int num) {
test_code: using System;
  using System.Numerics;
  using System.Diagnostics;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using System.Security.Cryptography;
  using System.Web.UI;
  using System.Web.Script.Serialization;
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  namespace EvaluatePrediction {
      class TestRunner {
          public bool ValidateSolution(bool actual, bool expected){
              return new JavaScriptSerializer().Serialize(actual) == new JavaScriptSerializer().Serialize(expected);
          }
  
          public string driver(int num, bool expected){
              try{
                PLACEHOLDER_CLS_NAME solution_cls = new PLACEHOLDER_CLS_NAME();
                bool pred_result = solution_cls.PLACEHOLDER_FN_NAME(num); 
                if (ValidateSolution(
                      pred_result,
                      expected)){
                  return "PASSED";
                }
                return "FAILED";
              } 
              catch (Exception exception_obj)
              {
                return exception_obj.GetType().FullName;
              }
          }
          static void Main(string[] args) {
              TestRunner runner = new TestRunner();
              String result;
              result = runner.driver(
                  1, 
                  true
              );
              Console.WriteLine(string.Format(
                  "TEST-0...{0}",
                  result)
              );result = runner.driver(
                  3, 
                  true
              );
              Console.WriteLine(string.Format(
                  "TEST-1...{0}",
                  result)
              );result = runner.driver(
                  6, 
                  true
              );
              Console.WriteLine(string.Format(
                  "TEST-2...{0}",
                  result)
              );result = runner.driver(
                  10, 
                  true
              );
              Console.WriteLine(string.Format(
                  "TEST-3...{0}",
                  result)
              );result = runner.driver(
                  55, 
                  true
              );
              Console.WriteLine(string.Format(
                  "TEST-4...{0}",
                  result)
              );result = runner.driver(
                  48, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-5...{0}",
                  result)
              );result = runner.driver(
                  63, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-6...{0}",
                  result)
              );result = runner.driver(
                  72, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-7...{0}",
                  result)
              );result = runner.driver(
                  16, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-8...{0}",
                  result)
              );result = runner.driver(
                  85, 
                  false
              );
              Console.WriteLine(string.Format(
                  "TEST-9...{0}",
                  result)
              );
          }
      }
  }
  
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;
  }