{ "data": { "question": { "questionId": "2237", "questionFrontendId": "2131", "boundTopicId": null, "title": "Longest Palindrome by Concatenating Two Letter Words", "titleSlug": "longest-palindrome-by-concatenating-two-letter-words", "content": "

You are given an array of strings words. Each element of words consists of two lowercase English letters.

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Create the longest possible palindrome by selecting some elements from words and concatenating them in any order. Each element can be selected at most once.

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Return the length of the longest palindrome that you can create. If it is impossible to create any palindrome, return 0.

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A palindrome is a string that reads the same forward and backward.

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Example 1:

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\nInput: words = ["lc","cl","gg"]\nOutput: 6\nExplanation: One longest palindrome is "lc" + "gg" + "cl" = "lcggcl", of length 6.\nNote that "clgglc" is another longest palindrome that can be created.\n
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Example 2:

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\nInput: words = ["ab","ty","yt","lc","cl","ab"]\nOutput: 8\nExplanation: One longest palindrome is "ty" + "lc" + "cl" + "yt" = "tylcclyt", of length 8.\nNote that "lcyttycl" is another longest palindrome that can be created.\n
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Example 3:

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\nInput: words = ["cc","ll","xx"]\nOutput: 2\nExplanation: One longest palindrome is "cc", of length 2.\nNote that "ll" is another longest palindrome that can be created, and so is "xx".\n
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Constraints:

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