title: Count Of Occurrences Of A 101 Pattern In A String
signature: def countOfOccurrencesOfA101PatternInAString(s: String) = {
test_code: import scala.collection.mutable.HashMap
  import scala.collection.immutable.HashSet
  
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  
  // TESTING CODE 
  // ============================================
  def validateSolution(actual: Int , expected: Int): Boolean = {
      actual.toString == expected.toString
  }
  
  def driver(s: String, expected: Int): String = {
      try {
          if (validateSolution(PLACEHOLDER_FN_NAME(s),expected)) {
              "PASSED"
          } else{
              "FAILED"
          }
      }catch{
          case e: Exception => {e.getClass.getName}
      }
  
  }
  object QuestionEvaluator extends App {
  
      println(s"TEST-0...${driver(
        "1001ab010abc01001", 
        2    
      )}")   
  
  
      println(s"TEST-1...${driver(
        "1001010001", 
        3    
      )}")   
  
  
      println(s"TEST-2...${driver(
        "010100010100", 
        3    
      )}")   
  
  
      println(s"TEST-3...${driver(
        "DLCu", 
        0    
      )}")   
  
  
      println(s"TEST-4...${driver(
        "7072430592", 
        0    
      )}")   
  
  
      println(s"TEST-5...${driver(
        "011", 
        0    
      )}")   
  
  
      println(s"TEST-6...${driver(
        "pnJpypYOza", 
        0    
      )}")   
  
  
      println(s"TEST-7...${driver(
        "1037", 
        0    
      )}")   
  
  
      println(s"TEST-8...${driver(
        "111", 
        0    
      )}")   
  
  
      println(s"TEST-9...${driver(
        "HxK", 
        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;
  }