Can anybody that had WA7 give me some hints?
Thanks

Maybe that's because you didn't calculate the right shortest-path with the least boots changed(that is, your first number of the output is wrong, but the other one is right). I've got WA7 because I used only one bfs to calculate both values. 2 bfs should be used. (BTW, some of my classmates said only one bfs could also work??? I'm not sure about this.