134. Gas Station

class Solution {
    public int canCompleteCircuit(int[] gas, int[] cost) {
        int before = 0;
        int total = 0;
        int loc = 0;
        
        for (int i = 0; i < gas.length; i++) {
            before += gas[i] - cost[i];
            total += gas[i] - cost[i];
            
            if (before < 0) {
                loc = i + 1;
                before = 0;
            }
        }
        
        return total >= 0 ? loc : -1;
    }
}

Runtime: 0 ms, faster than 100.00% of Java online submissions for Gas Station.
Memory Usage: 39 MB, less than 83.31% of Java online submissions for Gas Station.