title: Minimum Number Of Bracket Reversals Needed To Make An Expression Balanced
signature: function minimumNumberOfBracketReversalsNeededToMakeAnExpressionBalanced(expr: string): number {
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.entry_cls_name: Solution
question_info.test_code: 
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  function convertToString(value: any): string{
      return JSON.stringify(value, function (key, val) {
          if (val instanceof Set) {
              return Array.from(val);
          } return val;});
  }
  
  function validateSolution(actual: number, expected: number): boolean {
      return convertToString(actual) === convertToString(expected);
  }
  
  function driver(expr: string, expected:number): string {
      try{
          if (validateSolution(PLACEHOLDER_FN_NAME(expr),expected)){
              return "PASSED";
          }
          return "FAILED";
      } catch (error) {
        return error.name;
      }
      
  }
      
  function main(){
    let result = '';
    result = driver("}{", 1);
    console.log(`TEST-0...${result}`);
  
    result = driver("{{{", -1);
    console.log(`TEST-1...${result}`);
  
    result = driver("{{{{", 2);
    console.log(`TEST-2...${result}`);
  
    result = driver("{{{{}}", 3);
    console.log(`TEST-3...${result}`);
  
    result = driver("}{{}}{{{", 4);
    console.log(`TEST-4...${result}`);
  
    result = driver("{}", 1);
    console.log(`TEST-5...${result}`);
  
    result = driver("", 0);
    console.log(`TEST-6...${result}`);
  
    result = driver("8", -1);
    console.log(`TEST-7...${result}`);
  
    result = driver("01111000", 4);
    console.log(`TEST-8...${result}`);
  
    result = driver("XPkERzHcpId", -1);
    console.log(`TEST-9...${result}`);
  
  };
  
  main();
question_info.extension: ts
question_info.entry_fn_name: minimumNumberOfBracketReversalsNeededToMakeAnExpressionBalanced
question_info.test_case_ids: 0 1 2 3 4 5 6 7 8 9
question_info.commands: tsc --target es2020 --lib es5,dom,es2015,es2020 __FILENAME__
question_info.commands: node __FILENAME__.js