bool isRoute(int src, int dst){
q.push(src);
visited[src] = true;
while(!q.isEmpty()){
int tmp = q.front();
q.pop();
// after pop from queue, the visiting is finished
if(tmp == dst)
return true;
for(int i=0; i<n; i++){
// visit neighbors with false visited state
if(visited[i] == false){
q.push(i);
visited[i] = true
}
}
}
