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:

 1     public int canCompleteCircuit(int[] gas, int[] cost) {
 2
 3         for (int i = 0; i < gas.length; i++) {
 4             int total = 0;
 5             int j = 0;
 6             for (; j < gas.length; j++) {
 7                 total += gas[(i+j) % gas.length] - cost[(i+j) % gas.length];
 8
 9                 if (total < 0) {
10                     i += j;
11                     break;
12                 }
13             }
14
15             if (j == gas.length) {
16                 return i;
17             }
18         }
19
20         return -1;
21     }

Problem Gas Station