comefrom: <doocs>1963.Minimum Number of Swaps to Make the String Balanced_1.py
code: def minSwaps( s: str) -> int:
      ans = 0
      for c in s:
          if c == '[':
              ans += 1
          elif ans:
              ans -= 1
      return (ans + 1) >> 1
masked: def sample_funcname ( var_0 : str ) -> int :
      var_4 = 0
      for var_5 in var_0 :
          if var_5 == '[' :
              var_4 += 1
          elif var_4 :
              var_4 -= 1
      return ( var_4 + 1 ) >> 1
  