Gas Station

There are N gas stations along a circular route, where the amount of gas at station i is gas[i].

You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to its next station (i+1). You begin the journey with an empty tank at one of the gas stations.

Return the starting gas station's index if you can travel around the circuit once, otherwise return -1.

Note:

The solution is guaranteed to be unique.

public class Solution {public int canCompleteCircuit(int[] gas, int[] cost) {int N = gas.length;for (int i = 0; i < N; i++) {int gasLeft = 0;boolean canFlag = true;for (int j = i; j < N; j++) {if(gasLeft + gas[j] < cost[j]){canFlag = false;break;}else{gasLeft += gas[j] - cost[j];}}if(canFlag){for (int j = 0; j < i; j++) {if(gasLeft + gas[j] < cost[j]){canFlag = false;break;}else{gasLeft += gas[j] - cost[j];}}}if(canFlag){return i;}}return -1;}}