class Solution {
    public int findCheapestPrice(int n, int[][] flights, int src, int dst, int K) {

        int[][] g = new int[n][n];
        for(int[] flight : flights){
            int source = flight[0], target = flight[1], cost = flight[2];
            g[source][target] = cost;
        }

        PriorityQueue<int[]> heap = new PriorityQueue<>(new Comparator<int[]>(){
           public int compare(int[] o1, int[] o2){
               return Integer.compare(o1[2], o2[2]);
           }
        });

        //int array with node, stops, price.
        heap.offer(new int[]{src, K+1, 0});

        while(!heap.isEmpty()){
            int[] curr = heap.poll();
            int vert = curr[0], remStops = curr[1], price = curr[2];

            if(vert == dst) return price;

            if(remStops > 0){
                for(int i = 0; i<n; i++){
                    if(g[vert][i] > 0){
                        heap.offer(new int[]{i, remStops - 1, price+g[vert][i]});
                    }
                }
            }
        }
        return -1;
    }
}