comefrom: <qiyuangong>367_Valid_Perfect_Square_2.py
code: def isPerfectSquare( num):
      low, high = 1, num
      while low <= high:
          mid = (low + high) / 2
          mid_square = mid * mid
          if mid_square == num:
              return True
          elif mid_square < num:
              low = mid + 1
          else:
              high = mid - 1
      return False
masked: def sample_funcname ( var_0 ) :
      var_2 , var_3 = 1 , var_0
      while var_2 <= var_3 :
          var_5 = ( var_2 + var_3 ) / 2
          var_6 = var_5 * var_5
          if var_6 == var_0 :
              return True
          elif var_6 < var_0 :
              var_2 = var_5 + 1
          else :
              var_3 = var_5 - 1
      return False
  