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AtCoder testcases

All testcases of all future AtCoder official contests will be posted at

AtCoder Grand Contest 002 Announcement

[AtCoder Grand Contest 002]( will be held on Sunday. - Time: July 31st (Sunday), [21:00 JST]( - Duration: <font color="red">110</font> minutes - Number of Tasks: 6 - Writer: <a href="/user/sugim48" class="username"><span class="user-yellow">sugim48</span></a> - Rated: Yes We are looking forward to your participation! The point values are 200 (100), 400, 500, 1000, 1400, 1600.

AtCoder Rating System

The ratings were updated last Sunday, but it turned out that in the old rating system the ratings changed too much in a single contest. We changed the rating formula to fix this issue, and now the rating is calculated based on the new system. In AtCoder, when you participate in only a few contests your rating is much lower than your actual strength (so don't worry even if your current rating is very low). You need to participate in at least 10 contests in order to get accurate rating. We will publish the rating formula in the near future. Here is the table of colors: |Rating|Color| |:--:|:--:| |3600-3999|???| |3200-3599|???| |2800-3199|<span class="user-red">Red</span>| |2400-2799|<span class="user-orange">Orange</span>| |2000-2399|<span class="user-yellow">Yellow</span>| |1600-1999|<span class="user-blue">Blue</span>| |1200-1599|<span class="user-cyan">Cyan</span>| |800-1199|<span class="user-green">Green</span>| |400-799|<span class="user-brown">Brown</span>| |0-399|<span class="user-gray">Gray</span>|

AtCoder Regular Contest 058 / Beginner Contest 042 Announcement

Two contests [AtCoder Regular Contest 058]( and [AtCoder Beginner Contest 042]( will be held on this Saturday at the same time. You can participate in whichever contest you want. (However, you can't register to both competitions.) The last two tasks in ABC are the same as the first two tasks in ARC. ABC is significantly easier than Div2 contest in TopCoder of Codeforces. If you can enjoy Div2 contests in TC or CF, I recommend you to participate in ARC. - Time: July 23rd (Saturday), [21:00 JST]( - Duration: 100 minutes - Number of Tasks: 4 - Writer:<a href="/user/yosupo" class="username"><span class="user-yellow">yosupo</span></a>, <a href="/user/kyuridenamida" class="username"><span class="user-green">kyuridenamida</span></a> - Rating: ARC is rated for those who have rating < 2800. ABC is rated for those who have rating < 1200. (However, note that current rating is much lower than your actual strength - if you are green or brown, I recommend you to choose ARC.) The point values are: - ARC: 300 - 400 - 700 - 1500 - ABC: 100 - 200 - 300 - 400 You can check the relation between point values and difficulties [here]( We are looking forward to your participation! **UPD:** Thank you for participation! **UPD:** Ratings are updated.

AtCoder Grand Contest 001 Announcement

The first international contest, [AtCoder Grand Contest 001](, will be held on Saturday. - Time: July 16th (Saturday), [21:00 JST]( - Duration: <font color="red">110</font> minutes - Number of Tasks: 6 - Writer: <a href="/user/snuke" class="username"><span class="user-unrated">snuke</span></a> - Rated: Yes Each task is assigned a point value. For example, if you solve a 100-point problem correctly, you will get 100 points. Your solution will be judged soon after your submission (like ICPC). The contestants are ranked by the total scores. In case of tie, they are ranked by the penalties. The penalty is computed as (the time you spent to get current score) plus (5 minutes) * (the number of incorrect attempts). We are looking forward to your participation! The point values are 200, 500 (300 for partial task), 600, 1000, 1400, 2000. **UPD:** The editorial is uploaded. [editorial link]( (English is at the bottom) **UPD:** Ratings are updated! **UPD:** The contest winners were: 1. <a href="/user/cgy4ever" class="username"><span class="user-red">cgy4ever</span></a> 2. <a href="/user/DEGwer" class="username"><span class="user-red">DEGwer</span></a> 3. <a href="/user/Um_nik" class="username"><span class="user-red">Um_nik</span></a> 4. <a href="/user/yosupo" class="username"><span class="user-orange">yosupo</span></a> 5. <a href="/user/jcvb" class="username"><span class="user-orange">jcvb</span></a> Congratulations! You can see the statistics [here]( In AGC 001, 949 coders participated from 53 countries. Here is the list of countries with at least 5 participants: - Japan: 703 - India: 83 - China: 33 - Russia: 23 - Bangladesh: 22 - Afghanistan: 13 - Iran: 12 - United States: 12 - Ukraine: 10 - Vietnam: 10 - Belarus: 8 - Poland: 7 - Taiwan: 7 - Egypt: 5