comefrom: <doocs>1064.Fixed Point_1.py
code: def fixedPoint( arr: List[int]) -> int:
      left, right = 0, len(arr) - 1
      while left < right:
          mid = (left + right) >> 1
          if arr[mid] >= mid:
              right = mid
          else:
              left = mid + 1
      return left if arr[left] == left else -1
masked: def sample_funcname ( var_0 : List [ int ] ) -> int :
      var_4 , var_7 = 0 , len ( var_0 ) - 1
      while var_4 < var_7 :
          var_8 = ( var_4 + var_7 ) >> 1
          if var_0 [ var_8 ] >= var_8 :
              var_7 = var_8
          else :
              var_4 = var_8 + 1
      return var_4 if var_0 [ var_4 ] == var_4 else - 1
  