title: Count Of Occurrences Of A 101 Pattern In A String
signature: countOfOccurrencesOfA101PatternInAString(s) {
test_code: import 'dart:convert';
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  bool validateSolution(int actual, int expected){
      return actual.toString() == expected.toString();
  }
  
  String driver(s, int expected){
      try
      {
          if (validateSolution(PLACEHOLDER_FN_NAME(s), expected)){
              return "PASSED";
          }
          return "FAILED";
      }catch(exception_object){
          return exception_object.runtimeType.toString();
      }
  }
  
  int main() {
  
      print("TEST-0...${driver(
          "1001ab010abc01001", 
          2)
      }");
  
      print("TEST-1...${driver(
          "1001010001", 
          3)
      }");
  
      print("TEST-2...${driver(
          "010100010100", 
          3)
      }");
  
      print("TEST-3...${driver(
          "DLCu", 
          0)
      }");
  
      print("TEST-4...${driver(
          "7072430592", 
          0)
      }");
  
      print("TEST-5...${driver(
          "011", 
          0)
      }");
  
      print("TEST-6...${driver(
          "pnJpypYOza", 
          0)
      }");
  
      print("TEST-7...${driver(
          "1037", 
          0)
      }");
  
      print("TEST-8...${driver(
          "111", 
          0)
      }");
  
      print("TEST-9...${driver(
          "HxK", 
          0)
      }");
  
      return 0;
  }
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;
  }