comefrom: <doocs>0134.Gas Station_1.py
code: def canCompleteCircuit( gas: List[int], cost: List[int]) -> int:
      n = len(gas)
      i = j = n - 1
      cnt = s = 0
      while cnt < n:
          s += gas[j] - cost[j]
          cnt += 1
          j = (j + 1) % n
          while s < 0 and cnt < n:
              i -= 1
              s += gas[i] - cost[i]
              cnt += 1
      return -1 if s < 0 else i
masked: def sample_funcname ( var_0 : List [ int ] , var_3 : List [ int ] ) -> int :
      var_5 = len ( var_0 )
      var_8 = var_6 = var_5 - 1
      var_11 = var_9 = 0
      while var_11 < var_5 :
          var_9 += var_0 [ var_6 ] - var_3 [ var_6 ]
          var_11 += 1
          var_6 = ( var_6 + 1 ) % var_5
          while var_9 < 0 and var_11 < var_5 :
              var_8 -= 1
              var_9 += var_0 [ var_8 ] - var_3 [ var_8 ]
              var_11 += 1
      return - 1 if var_9 < 0 else var_8
  