Have you ever been curious about what red coders do during a contest in order to solve all problems within a contest? How they think? How they debug?
You can check out my screencast here: https://youtu.be/jQHY_0vi8Oc (note that it’s almost 3 hours long)
I don’t describe solutions very well while doing the contest though, look at January Lunchtime 2020 Post-Contest Discussion Stream if you are looking for solutions instead.