Codeforces
codforces.com
Probably the biggest one among competitive programming websites.
There are two ways to solve problem.
- Find the constest, join and solve the problem.
- Solve past contest’s problem.
And there is division system which groups participants depends on their ratings.
| Division name | Range of ratings to participate | Range of participant’s ratings influenced |
|---|---|---|
| Div. 1 + Div. 2 | All | All |
| Div. 1 (When Div. 2 is held at the same time) | 1900-9999 | 1900-9999 |
| Div. 2 (When Div. 1 is held at the same time) | 0-1899 | 0-1899 |
| Div. 2 only | All | 0-2099 |
| Div. 3 | All | 0-1599 |
| Div. 4 | All | 0-1399 |
| Unrated | All | None |
AtCoder
atcoder.jp
ICPC Global
icpc.global
SPOJ
spoj.com
ProgVar
progvar.fun
Google Code Jam
codingcompetitions.withgoogle.com/codejam
You can submit past problem’s solution in Archive tab.
Google Kick Start
codingcompetitions.withgoogle.com/kickstart
You can submit past problem’s solution in Archive tab.
Google Hashcode
https://codingcompetitions.withgoogle.com/hashcode
You can view and download past problems in Archive tab.