We will hold AtCoder Regular Contest 140.

• Contest URL: https://atcoder.jp/contests/arc140
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20220515T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: PCTprobability, nok0
• Tester: Nyaan
• Rated range: — 2799

The point values will be 300-400-500-700-800-900.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 057. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc057
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20220507T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 6
• Writer: maspy
• Tester: HIR180, tatyam
• Rated range: 1200 -

The point values will be 400-700-1100-1100-1400-1800.

We are looking forward to your participation!

This is the first contest in the 2022 season that counts for the GP30 race. We are planning to invite top runners of the race to WTF 2023, but we still haven't decided on the details of the Finals. We will closely watch the domestic and international situations and consider when and how to hold the Finals. We are also trying to find a way to hold unfinished WTF 2020, 2021, and 2022.

We will hold AtCoder Regular Contest 139.

• Contest URL: https://atcoder.jp/contests/arc139
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20220424T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: PCTprobability, Nyaan
• Tester: maspy
• Rated range: — 2799

The point values will be 300-500-700-700-800-1000.

We are looking forward to your participation!

We will hold Daiwa Securities Co. Ltd. Programming Contest 2022 Spring（AtCoder Regular Contest 138）.

• Contest URL: https://atcoder.jp/contests/arc138
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20220409T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, satashun
• Rated range: — 2799

The point values will be 400-500-600-700-1000-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 137.

• Contest URL: https://atcoder.jp/contests/arc137
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20220319T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, Nyaan
• Rated range: — 2799

The point values will be 300-400-600-700-800-1100.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 136.

• Contest URL: https://atcoder.jp/contests/arc136
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20220227T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, Nyaan
• Rated range: — 2799

The point values will be 300-400-500-600-800-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 135.

• Contest URL: https://atcoder.jp/contests/arc135
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20220213T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maspy
• Tester: HIR180, tatyam
• Rated range: — 2799

The point values will be 300-500-500-700-800-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 134.

• Contest URL: https://atcoder.jp/contests/arc134
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20220129T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: camypaper
• Tester: maspy, satashun
• Rated range: — 2799

The point values will be 300-400-500-600-900-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 133.

• Contest URL: https://atcoder.jp/contests/arc133
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20220122T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk, yosupo
• Tester: maspy, Nyaan
• Rated range: — 2799

The point values will be 300-500-500-700-800-1100.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 132.

• Contest URL: https://atcoder.jp/contests/arc132
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20211226T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: nuip
• Tester: maspy, satashun
• Rated range: — 2799

The point values will be 400-400-600-700-800-900.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 131.

• Contest URL: https://atcoder.jp/contests/arc131
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20211205T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: E869120, square1001
• Tester: tempura0224
• Rated range: — 2799

The point values will be 300-300-600-600-600-1000.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 056. This contest counts for GP30 scores, and this is the final AGC of this year.

• Contest URL: https://atcoder.jp/contests/agc056
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20211204T2100&p1=248
• Duration: 180 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, yamunaku
• Rated range: 1200 -

The point values will be 300-900-900-1600-1600-1600.

We are looking forward to your participation!

As discussed in my previous blog, we are going to introduce a new system for Rated/Unrated participation. It will take effect from this weekend's contests (ABC, AGC, and ARC). See this post for details.

If you have any questions, please leave them here.

We will hold AtCoder Regular Contest 130.

• Contest URL: https://atcoder.jp/contests/arc130
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20211128T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maspy
• Tester: HIR180, tempura0224
• Rated range: — 2799

The point values will be 300-400-500-600-800-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 129.

• Contest URL: https://atcoder.jp/contests/arc129
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20211121T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, satashun
• Rated range: — 2799

The point values will be 300-400-500-600-900-1000.

We are looking forward to your participation!

We will hold Daiwa Securities Co. Ltd. Programming Contest 2021（AtCoder Regular Contest 128）.

• Contest URL: https://atcoder.jp/contests/arc128
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20211016T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, yamunaku
• Rated range: — 2799

The point values will be 400-400-600-700-800-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 127.

Please note the unusual start time (1 hour earlier than usual).

• Contest URL: https://atcoder.jp/contests/arc127
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20210925T2000&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, tempura0224
• Rated range: — 2799

The point values will be 300-500-500-700-800-1000.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 126. Please note the unusual start time (1 hour later than usual)

• Contest URL: https://atcoder.jp/contests/arc126
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20210919T2200&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maspy
• Tester: satashun, tempura0224
• Rated range: — 2799

The point values will be 300-400-600-600-800-1100.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 125.

• Contest URL: https://atcoder.jp/contests/arc125
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20210822T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, yamunaku
• Rated range: — 2799

The point values will be 300-500-600-700-800-900.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 124.

• Contest URL: https://atcoder.jp/contests/arc124
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20210725T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: camypaper
• Tester: tatyam, maspy
• Rated range: — 2799

The point values will be 300-400-500-700-800-900.

We are looking forward to your participation!

We will hold AtCoder Regular Contest 123.

• Contest URL: https://atcoder.jp/contests/arc123
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20210718T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maspy
• Tester: tatyam, tempura0224
• Rated range: — 2799

The point values will be 300-400-600-700-700-1000.

We are looking forward to your participation!

We will hold AtCoder Grand Contest 054. This contest counts for GP30 scores.

• Contest URL: https://atcoder.jp/contests/agc054
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20210627T2100&p1=248
• Duration: 150 minutes
• Number of Tasks: 6
• Writer: yosupo, sigma425, maroonrk, wo_
• Tester: satashun, HIR180
• Rated range: 1200 -

The point values will be 300-800-800-1000-1200-1800.

We are looking forward to your participation!

After the last ARC, one participant pointed out that the result is WA when the error is precisely the same as $$$EPS$$$ (submission).

For example, consider these two outputs: 331997010.50000000000000000000 (the jury output) and 331997342.4970105 (the user output). Their relative error is exactly $$$10^{-6}$$$, so when $$$EPS=10^{-6}$$$, this should get AC.

However, with the current implementation of the doubleCompare function in testlib.h, the result is WA. This is because perturbations in the line 429 (return result + 1E-15 >= minv && result <= maxv + 1E-15;) don't work when the values of result/minv/maxv are large. We made a fix and sent a pull request.

If you believe you were affected by this in the last ARC, please let me know.

That being said, given the popularity of testlib.h and the fact that no one has ever raised this issue, I hope no one was affected by this in the entire history of testlib.h.

We will hold Tokio Marine & Nichido Fire Insurance Programming Contest 2021（AtCoder Regular Contest 122).

• Contest URL: https://atcoder.jp/contests/arc122
• Start Time: http://www.timeanddate.com/worldclock/fixedtime.html?iso=20210612T2100&p1=248
• Duration: 120 minutes
• Number of Tasks: 6
• Writer: maroonrk
• Tester: maspy, yamunaku
• Rated range: — 2799

The point values will be 400-500-600-700-800-1200.

We are looking forward to your participation!

As of now, there is no blog, so I'll post this.

How to solve C Large without complex casework?