[LeetCode][Python3] 134. Gas Station

Problem :

https://leetcode.com/problems/gas-station/

My Solution :

class Solution:

def canCompleteCircuit(self, gas, cost):

before = tank = start = 0

for i in range(len(gas)):

tank += (gas[i] - cost[i])

if tank < 0:

before += tank

tank = 0

start = i+1

return start if 0 <= before + tank else -1