【遞推】codeforces1140E Palindrome-less Arrays

1140E Palindrome-less Arrayshtml Let’s denote that some array b is bad if it contains a subarray bl,bl+1,…,br of odd length more than 1 (l<r and r−l+1 is odd) such that ∀i∈{0,1,…,r−l} bl+i=br−i.web If

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