- Pavel Mavrin's Algorithms and Data Structures course playlist on Youtube
Host contests
Doesn't host contests
- CSES problem set
- Atcoder archived contest problems
- Codeforces archived contest problems
- Codechef archived contest problems
- DMOJ archived contest problems
- TLX archived contest problems
- Timus problem set
- Kattis problems
- Project Euler problem archives
How do I start competitive programming?
- Maybe by giving one contest on any of the platform listed above!
How do I practice?
- Codeforces blog by Radewoosh titled "My opinion on how to practice competitive programming"
- Codeforces blog by Um_nik titled "How to practice Competitive Programming [Um_nik version]"
- Codeforces blog by Geothermal titled "Thoughts on Reaching Cyan?"
- Codeforces blog by -is-this-fft- titled "Self-deception: maybe why you're still grey after practicing every day"
How do I know about upcoming contests in one place?
- Join the discord server, Errichto Server Official and get the
Contestant
server role. - Check the clist.by website.
How do I resolve my doubts and (virtually) meet like-minded people?
- You can join several online CP communities; links are below (in no particular order).
- Discord servers
- Telegram groups/channels
- WhatsApp groups
I'm still working on this list, so it's not the end.