Problem Gas Station

Problem Description:

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.

 

Solution:

    public int canCompleteCircuit(int[] gas, int[] cost) {
    
        for (int i = 0; i < gas.length; i++) {
            int total = 0;
            int j = 0;
            for (; j < gas.length; j++) {
                total += gas[(i+j) % gas.length] - cost[(i+j) % gas.length];

                if (total < 0) {
                    i += j;
                    break;
                }
            }

            if (j == gas.length) {
                return i;
            } 
        }

        return -1;
    }