Dear friends,
Today I tried an experimental format: separate videos. So, today I participated in Codeforces Round 896 (Div. 1) and recorded a screencast, but, unlike the previous times, I did not immediately record the editorials. Instead several videos are dedicated to them. So here are the links:
- https://youtu.be/uuyVZcExbEI — screencast of Codeforces Round 896 (Div. 1);
- https://youtu.be/OFKF3oGhvmE — editorial (and upsolving!) of 1869A - Сделайте это нулём;
- https://youtu.be/JoUOqDvKHuo — editorial (and upsolving!) of 1869B - 2D Путешествие;
- https://youtu.be/iS3eusWsx3E — editorial of 1869C - Заполните матрицу (if you're interested in the coding part, you can find it here: https://youtu.be/uuyVZcExbEI?t=938);
- https://youtu.be/1Vu2RSQg0D0 — editorial of 1869D1 - Конфетная вечеринка (простая версия) and 1869D2 - Конфетная вечеринка (сложная версия) (if you're interested in the coding part, you can find it here: https://youtu.be/uuyVZcExbEI?t=2688);
- https://youtu.be/Zn2OkKlgaG0 — editorial of 1869E - План путешествия (if you're interested in the coding part, you can find it here: https://youtu.be/uuyVZcExbEI?t=5204);
- https://youtu.be/i4RO3x1fmjA — editorial (and long, long upsolving!) of 1869F - Цветочное псевдодерево.
UPD: I recorded the upsolving of 1869F - Цветочное псевдодерево (see the link above). I guess my explanation was quite fine, but in one case I incorrectly calculated the preconditions, which resulted in a huge mess and pain. It is still quite educational stuff though: the first half of the video is just a normal editorial (but, alas, with a technical mistake which should't screw the flow of the problem though), and the second one can teach you how to seek for bugs in problems like this one (with a big number of cases).