Anecdote: An online judge website (which is pretty well known in Korea) has an easy problem[0] asking to write a program which adds "??!" to input. A lot of beg

Anecdote: An online judge website (which is pretty well known in Korea) has an easy problem[0] asking to write a program which adds "??!" to input. A lot of beginners' C/C++ submissions got "Wrong Answer" verdict because of trigraphs. [0]: https://www.acmicpc.net/problem/10926 https://www.acmicpc.net/problem/10926