Hello. Every week, I will discuss few nice recent problems from CF, AC, CC. I will alternate between div2 and div1 streams, with difficulties [1400, 1800] and ~[2200, 2800] respectively. Try to solve problems on your own before each stream!
You can suggest new cool/interesting/educational problems in comments below this blog.

2.10.2021, Div2 Problems of the Week https://youtu.be/AbeEJvmsx0E

1. [1800] 1572A - Book
2. [1600] 1567C - Carrying Conundrum
3. [1800] 1556C - Compressed Bracket Sequence + O(N) solution

honorable mentions
- [1700] 1579E2 - Array Optimization by Deque
- [1800?] Cross-free Matching https://atcoder.jp/contests/arc126/tasks/arc126_b

9.10.2021, Div1 Problems of the Week https://youtu.be/7rtZEXAVzmk

1. [2400] 1592E - Bored Bakry
2. [2700] 1572C - Paint
3. [3000] 1572E - Polygon