title: Count Of Occurrences Of A 101 Pattern In A String
signature: class Solution {
  
      public int CountOfOccurrencesOfA101PatternInAString(string s) {
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(int actual, int expected){
              return new JavaScriptSerializer().Serialize(actual) == new JavaScriptSerializer().Serialize(expected);
          }
  
          public string driver(string s, int expected){
              try{
                PLACEHOLDER_CLS_NAME solution_cls = new PLACEHOLDER_CLS_NAME();
                int pred_result = solution_cls.PLACEHOLDER_FN_NAME(s); 
                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(
                  "1001ab010abc01001", 
                  2
              );
              Console.WriteLine(string.Format(
                  "TEST-0...{0}",
                  result)
              );result = runner.driver(
                  "1001010001", 
                  3
              );
              Console.WriteLine(string.Format(
                  "TEST-1...{0}",
                  result)
              );result = runner.driver(
                  "010100010100", 
                  3
              );
              Console.WriteLine(string.Format(
                  "TEST-2...{0}",
                  result)
              );result = runner.driver(
                  "DLCu", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-3...{0}",
                  result)
              );result = runner.driver(
                  "7072430592", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-4...{0}",
                  result)
              );result = runner.driver(
                  "011", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-5...{0}",
                  result)
              );result = runner.driver(
                  "pnJpypYOza", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-6...{0}",
                  result)
              );result = runner.driver(
                  "1037", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-7...{0}",
                  result)
              );result = runner.driver(
                  "111", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-8...{0}",
                  result)
              );result = runner.driver(
                  "HxK", 
                  0
              );
              Console.WriteLine(string.Format(
                  "TEST-9...{0}",
                  result)
              );
          }
      }
  }
  
source_py: def count_of_occurrences_of_a_101_pattern_in_a_string(s):
      length = len(s)
      oneSeen = False
      count = 0
      for i in range(length):
          if ((s[i] == '1') and oneSeen):
              if (s[(i - 1)] == '0'):
                  count += 1
          if ((s[i] == '1') and (oneSeen == 0)):
              oneSeen = True
          if ((s[i] != '0') and (s[i] != '1')):
              oneSeen = False
      return count
source_cpp: int count_of_occurrences_of_a_101_pattern_in_a_string(string str) {
    int len = str . size ( );
    bool oneSeen = 0;
    int count = 0;
    for ( int i = 0;
    i < len;
    i ++ ) {
      if ( str [ i ] == '1' && oneSeen == 1 ) if ( str [ i - 1 ] == '0' ) count ++;
      if ( str [ i ] == '1' && oneSeen == 0 ) {
        oneSeen = 1;
        continue;
      }
      if ( str [ i ] != '0' && str [ i ] != '1' ) oneSeen = 0;
    }
    return count;
  }