public static void main(String args[]){
        GasStationCircle gsc = new GasStationCircle();
        int[] gasAvailable = {4, 4, 6};
        int[] gasRequired = {5, 6, 1};
        System.out.println(gsc.startTour(gasAvailable, gasRequired));
        System.out.println(gsc.startTour1(gasAvailable, gasRequired));
    }
If it is not guaranteed that tour exists then once you get
result of kadanewrap make an actual trip to see if value is positive
@return -1 if no solution exists otherwise returns gas station at which to start.
src/com/interview/array/GasStationCircle.java