I want to invite you to participate in HackerEarth September Clash '15. It is 24h-long contest, scheduled on September, 19 (check your timezone). Problemset consists of 5 algorithmic tasks of varying difficulty with partial solutions allowed - you get points for every test that you solution passed, and one approximate problem - your score for this task depends on how good your solution is comparing to current best solution.
Problemset was prepared by Lewin Gan - he already prepared a few interesting contests at TopCoder and Codeforces before, and now you have an opportunity to solve his problems at HackerEarth I was co-working with him as a tester.
There will be nice prizes for toppers:
Amazon Gift Cards for top3 ($100 - 80 - 50)
HackerEarth T-shirts for top5.