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### ggok's blog

By ggok, history, 4 years ago, ,

Hi, I recently came across this question and i have no idea how to approach it.

You are given a number N (3 ≤ N ≤ 100000) and you should create a permutation of the first N numbers.

The permutation should not have an arithmetic subsequence with three or more terms in it.

for example

5             4 2 3 1 5
3             3 1 2

• 0

 » 4 years ago, # |   +3 Take a look at this problem (and its solution). http://codeforces.com/contest/452/problem/F