https://codeforces.com/blog/entry/224
https://codeforces.com/blog/entry/512
http://forum.mmcs.sfedu.ru/t/sportivnoe-programmirovanie-dlya-studentov/661/50
https://www.topcoder.com/community/competitive-programming/tutorials/power-up-c-with-the-standard-template-library-part-1/
https://tproger.ru/tag/competitive-programming/
https://habr.com/ru/post/128108/
http://www.cyberforum.ru/blogs/295147/

https://www.twirpx.com/files/informatics/languages/olympics/
https://nashol.me/vse-knigi-po-informatike/