comefrom: <garvit244>268_1.py
code: def missingNumber( nums):
      if not nums:
          return 0
      totalSum, n = sum(nums), len(nums)
      expectedSum = (n*(n+1))/2
      return expectedSum - totalSum
masked: def sample_funcname ( var_0 ) :
      if not var_0 :
          return 0
      var_3 , var_5 = sum ( var_0 ) , len ( var_0 )
      var_8 = ( var_5 * ( var_5 + 1 ) ) / 2
      return var_8 - var_3
  