Very early on Wednesday, TopCoder SRM 705 set the pace for the competitions in 2017 (problems, results, top 5 on the left). Tourist would have been in the 7th place even if all his solutions failed the system test, thanks to an impressive challenge phase performance. And as usual, none of the solutions did fail, so he achieved an extremely commanding victory. Congratulations!

Later that day, Codeforces held its own opening contest of 2017 - Codeforces Round 391 (problems, results, top 5 on the left, analysis). Once again tourist has combined excellent solving with excellent challenging to claim a win, but the competition was much closer this time. Well done to tourist and to his competitors!

On Sunday, Codeforces held one more round: 8VC Venture Cup 2017 Elimination Round (problems, results, top 5 on the left, analysis). In case you have not noticed the pattern of the new year, it was tourist at the top once again. Impressive consistency!

In my last summary, I have organized a vote between top 5 problems of 2016 (of course, only according to my taste). Here are its results:

5. The problem about recovering the seed used for shuffling a permutation twice - post with solution. 13 votes, author: Ivan Kazmenko.

4. The problem about turning one string into another using two operations: replace one letter, or replace all occurrences of the same letter - post with solution. 17 votes, author: Adam Karczmarz.

3. The problem about exploring a cave with identical rooms interactively - post with solution. 21 vote, author: Georgiy Korneev.

2. The problem about implementing binary search that's takes at most log(n+1)+0.1 on average, not ceil(log(n)) - post with solution. 29 votes, author: Vasiliy Mokin (not sure, please tell if it's not correct).

1. The problem about turning a matching in the plane into a non-intersecting one that's at least 0.636x as long - post with solution. 37 votes, author: Gaoyuan Chen.

Big thanks to the authors of these and all other 2016 problems!

Later that day, Codeforces held its own opening contest of 2017 - Codeforces Round 391 (problems, results, top 5 on the left, analysis). Once again tourist has combined excellent solving with excellent challenging to claim a win, but the competition was much closer this time. Well done to tourist and to his competitors!

On Sunday, Codeforces held one more round: 8VC Venture Cup 2017 Elimination Round (problems, results, top 5 on the left, analysis). In case you have not noticed the pattern of the new year, it was tourist at the top once again. Impressive consistency!

In my last summary, I have organized a vote between top 5 problems of 2016 (of course, only according to my taste). Here are its results:

5. The problem about recovering the seed used for shuffling a permutation twice - post with solution. 13 votes, author: Ivan Kazmenko.

4. The problem about turning one string into another using two operations: replace one letter, or replace all occurrences of the same letter - post with solution. 17 votes, author: Adam Karczmarz.

3. The problem about exploring a cave with identical rooms interactively - post with solution. 21 vote, author: Georgiy Korneev.

2. The problem about implementing binary search that's takes at most log(n+1)+0.1 on average, not ceil(log(n)) - post with solution. 29 votes, author: Vasiliy Mokin (not sure, please tell if it's not correct).

1. The problem about turning a matching in the plane into a non-intersecting one that's at least 0.636x as long - post with solution. 37 votes, author: Gaoyuan Chen.

Big thanks to the authors of these and all other 2016 problems!