{ "data": { "question": { "questionId": "3143", "questionFrontendId": "2900", "boundTopicId": null, "title": "Longest Unequal Adjacent Groups Subsequence I", "titleSlug": "longest-unequal-adjacent-groups-subsequence-i", "content": "

You are given an integer n, a 0-indexed string array words, and a 0-indexed binary array groups, both arrays having length n.

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You need to select the longest subsequence from an array of indices [0, 1, ..., n - 1], such that for the subsequence denoted as [i0, i1, ..., ik - 1] having length k, groups[ij] != groups[ij + 1], for each j where 0 < j + 1 < k.

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Return a string array containing the words corresponding to the indices (in order) in the selected subsequence. If there are multiple answers, return any of them.

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A subsequence of an array is a new array that is formed from the original array by deleting some (possibly none) of the elements without disturbing the relative positions of the remaining elements.

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Note: strings in words may be unequal in length.

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Example 1:

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\nInput: n = 3, words = ["e","a","b"], groups = [0,0,1]\nOutput: ["e","b"]\nExplanation: A subsequence that can be selected is [0,2] because groups[0] != groups[2].\nSo, a valid answer is [words[0],words[2]] = ["e","b"].\nAnother subsequence that can be selected is [1,2] because groups[1] != groups[2].\nThis results in [words[1],words[2]] = ["a","b"].\nIt is also a valid answer.\nIt can be shown that the length of the longest subsequence of indices that satisfies the condition is 2.
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Example 2:

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\nInput: n = 4, words = ["a","b","c","d"], groups = [1,0,1,1]\nOutput: ["a","b","c"]\nExplanation: A subsequence that can be selected is [0,1,2] because groups[0] != groups[1] and groups[1] != groups[2].\nSo, a valid answer is [words[0],words[1],words[2]] = ["a","b","c"].\nAnother subsequence that can be selected is [0,1,3] because groups[0] != groups[1] and groups[1] != groups[3].\nThis results in [words[0],words[1],words[3]] = ["a","b","d"].\nIt is also a valid answer.\nIt can be shown that the length of the longest subsequence of indices that satisfies the condition is 3.\n
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Constraints:

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(listof string?) (listof exact-integer?) 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Compiled with clang 11 using the latest C++ 20 standard.

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Your code is compiled with level two optimization (-O2). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.

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Most standard library headers are already included automatically for your convenience.

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OpenJDK 17. Java 8 features such as lambda expressions and stream API can be used.

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Most standard library headers are already included automatically for your convenience.

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Python 2.7.12.

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Most libraries are already imported automatically for your convenience, such as array, bisect, collections. If you need more libraries, you can import it yourself.

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For Map/TreeMap data structure, you may use sortedcontainers library.

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3. Deleting an item in a hash:\\r\\n

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C# 10 with .NET 6 runtime

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Node.js 16.13.2.

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Ruby 3.1

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Some common data structure implementations are provided in the Algorithms module: https://www.rubydoc.info/github/kanwei/algorithms/Algorithms

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Swift 5.5.2.

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Go 1.21

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Python 3.10.

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Kotlin 1.9.0.

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