comefrom: <qiyuangong>134_Gas_Station_1.py
code: def canCompleteCircuit( gas, cost):
      ls = len(gas)
      begin, end = 0, ls - 1
      curr = gas[end] - cost[end]
      while begin < end:
          if curr >= 0:
              curr += gas[begin] - cost[begin]
              begin += 1
          else:
              end -= 1
              curr += gas[end] - cost[end]
      if curr >= 0:
          return end
      else:
          return -1
masked: def sample_funcname ( var_0 , var_1 ) :
      var_3 = len ( var_0 )
      var_5 , var_7 = 0 , var_3 - 1
      var_8 = var_0 [ var_7 ] - var_1 [ var_7 ]
      while var_5 < var_7 :
          if var_8 >= 0 :
              var_8 += var_0 [ var_5 ] - var_1 [ var_5 ]
              var_5 += 1
          else :
              var_7 -= 1
              var_8 += var_0 [ var_7 ] - var_1 [ var_7 ]
      if var_8 >= 0 :
          return var_7
      else :
          return - 1
  