Gas Station

01 · Question

There are n gas stations. You have two integer arrays gas and cost. Return the starting gas station index if you can travel around the circuit once, otherwise return -1.

02 · Solution

Reference solution

1def canCompleteCircuit(gas: List[int], cost: List[int]) -> int:
2    if sum(gas) < sum(cost):
3        return -1
4        
5    start = 0
6    tank = 0
7    for i in range(len(gas)):
8        tank += gas[i] - cost[i]
9        if tank < 0:
10            start = i + 1
11            tank = 0
12    return start

Jump Game II