From University of Waterloo, Nepean H.S.
Problems I'm planning to do:
https://dmoj.ca/problem/ccc01s2exact
https://dmoj.ca/problem/sssp
https://dmoj.ca/problem/anoisyclass#comment-6344
https://dmoj.ca/problem/ahardergame
https://dmoj.ca/problem/ds4
https://dmoj.ca/problem/ds3
https://dmoj.ca/problem/dmopc14c1p6
https://dmoj.ca/problem/dmopc15c7p5
BFS