#define MAX 100
#define INFINITY 9999999
int queue[MAX*(MAX-1)/2];
int topQueue = -1;
int front = 0;
int queueItemCount = 0;
void insert(int vertex) {
    queue[++topQueue] = vertex;
    queueItemCount ++;
}
void removeQueue() {
    queueItemCount --;
    front++;
}
int getData() {
    return queue[front];
}
int queue2[MAX*(MAX-1)/2];
void insert2(int i) {
    queue2[topQueue] = i;
}
int getData2() {
    return queue2[front];
}


int findCheapestPrice(int n, int** flights, int flightsSize, int* flightsColSize, int src, int dst, int K){
    int M[n][n];
    for (int i=0 ; i<n; i++)
        for ( int j=0; j<n; j++)
            M[i][j] = 0;
    for (int i=0; i<flightsSize; i++){
        M[flights[i][0]][flights[i][1]] = flights[i][2];
    }
    bool visited[n];
    int shortest_path[n];
    for (int i = 0; i<n; i++) {
        shortest_path[i] = INFINITY;
        visited[i] = false;
    }
    visited[src] = true;
    for (int j= 1; j<n; j++) {
        insert(j);
        insert2(K-1);
        if (M[src][j] != 0)
            shortest_path[j] = M[src][j];
    }
//    printf("%d",getData2());
 //   printf("%d", queueItemCount);
 //   for (int i=0; i<n; i++) 
   //     printf("%d  ", shortest_path[i]);
 //   printf("\n");
    while (queueItemCount != 0 && getData2()>=0) {
        int next = getData();
        // update cac khoang cach
     //   for (int i=0; i<n; i++) 
       //     printf("%d  ", shortest_path[i]);
        //printf("\n");
        for (int j=0; j<n; j++) 
            if (M[next][j] != 0) {
                if (shortest_path[next] + M[next][j] < shortest_path[j])
                    shortest_path[j] = shortest_path[next] + M[next][j];
            }
        //if (visited[
        if (visited[next]) {
            removeQueue();
        }
        else {
            visited[next] = true;
            for (int j=0; j<n; j++)
                if (M[next][j] != 0){
                    insert(j);
                    insert2(getData2()-1);
                }
        }
    }
    if (shortest_path[dst] == INFINITY)
        return -1;
    else
        return shortest_path[dst];

}