title: Minimum Number Of Bracket Reversals Needed To Make An Expression Balanced
signature: fun minimumNumberOfBracketReversalsNeededToMakeAnExpressionBalanced(expr: String): Int {
source_py: def minimum_number_of_bracket_reversals_needed_to_make_an_expression_balanced(expr):
      lenn = len(expr)
      if (lenn % 2):
          return (- 1)
      s = []
      for i in range(lenn):
          if ((expr[i] == '') and len(s)):
              if (s[0] == ''):
                  s.pop(0)
              else:
                  s.insert(0, expr[i])
          else:
              s.insert(0, expr[i])
      red_len = len(s)
      n = 0
      while (len(s) and (s[0] == '')):
          s.pop(0)
          n += 1
      return ((red_len // 2) + (n % 2))
source_cpp: int minimum_number_of_bracket_reversals_needed_to_make_an_expression_balanced(string expr) {
    int len = expr . length ( );
    if ( len % 2 ) return - 1;
    stack < char > s;
    for ( int i = 0;
    i < len;
    i ++ ) {
      if ( expr [ i ] == '}' && ! s . empty ( ) ) {
        if ( s . top ( ) == '{' ) s . pop ( );
        else s . push ( expr [ i ] );
      }
      else s . push ( expr [ i ] );
    }
    int red_len = s . size ( );
    int n = 0;
    while ( ! s . empty ( ) && s . top ( ) == '{' ) {
      s . pop ( );
      n ++;
    }
    return ( red_len / 2 + n % 2 );
  }
question_info.test_list: [{"idx": 0, "outputs": 1, "inputs": {"expr": "}{"}}, {"idx": 1, "outputs": -1, "inputs": {"expr": "{{{"}}, {"idx": 2, "outputs": 2, "inputs": {"expr": "{{{{"}}, {"idx": 3, "outputs": 3, "inputs": {"expr": "{{{{}}"}}, {"idx": 4, "outputs": 4, "inputs": {"expr": "}{{}}{{{"}}, {"idx": 5, "outputs": 1, "inputs": {"expr": "{}"}}, {"idx": 6, "outputs": 0, "inputs": {"expr": ""}}, {"idx": 7, "outputs": -1, "inputs": {"expr": "8"}}, {"idx": 8, "outputs": 4, "inputs": {"expr": "01111000"}}, {"idx": 9, "outputs": -1, "inputs": {"expr": "XPkERzHcpId"}}]
question_info.extension: kts
question_info.test_code: package main
  
  import kotlin.text.*
  import kotlin.math.*
  
  
  // SOLUTION CODE
  // ===================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE
  // ===================================
  fun validateSolution(actual:Int, expected:Int):Boolean{
    return actual.equals(expected)
  }
  fun driver(expr: String, expected:Int):String {
      try{
        if (validateSolution(PLACEHOLDER_FN_NAME(expr), expected)) {
                return "PASSED"
        }
        return "FAILED"
      } catch (e: Exception){
        return e::class.simpleName as String
      }
  
  }
  
  fun main() {
      var result: String = ""
      result = driver("}{", 1)
      println("TEST-0...${result}")
      
      result = driver("{{{", -1)
      println("TEST-1...${result}")
      
      result = driver("{{{{", 2)
      println("TEST-2...${result}")
      
      result = driver("{{{{}}", 3)
      println("TEST-3...${result}")
      
      result = driver("}{{}}{{{", 4)
      println("TEST-4...${result}")
      
      result = driver("{}", 1)
      println("TEST-5...${result}")
      
      result = driver("", 0)
      println("TEST-6...${result}")
      
      result = driver("8", -1)
      println("TEST-7...${result}")
      
      result = driver("01111000", 4)
      println("TEST-8...${result}")
      
      result = driver("XPkERzHcpId", -1)
      println("TEST-9...${result}")
      
          
  }
  
  main()
question_info.entry_fn_name: minimumNumberOfBracketReversalsNeededToMakeAnExpressionBalanced
question_info.entry_cls_name: Solution
question_info.test_case_ids: 0 1 2 3 4 5 6 7 8 9
question_info.commands: kotlinc -script __FILENAME__ -no-reflect -nowarn