{ "data": { "question": { "questionId": "2708", "questionFrontendId": "2573", "boundTopicId": null, "title": "Find the String with LCP", "titleSlug": "find-the-string-with-lcp", "content": "

We define the lcp matrix of any 0-indexed string word of n lowercase English letters as an n x n grid such that:

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Given an n x n matrix lcp, return the alphabetically smallest string word that corresponds to lcp. If there is no such string, return an empty string.

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A string a is lexicographically smaller than a string b (of the same length) if in the first position where a and b differ, string a has a letter that appears earlier in the alphabet than the corresponding letter in b. For example, "aabd" is lexicographically smaller than "aaca" because the first position they differ is at the third letter, and 'b' comes before 'c'.

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Example 1:

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\nInput: lcp = [[4,0,2,0],[0,3,0,1],[2,0,2,0],[0,1,0,1]]\nOutput: "abab"\nExplanation: lcp corresponds to any 4 letter string with two alternating letters. The lexicographically smallest of them is "abab".\n
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Example 2:

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\nInput: lcp = [[4,3,2,1],[3,3,2,1],[2,2,2,1],[1,1,1,1]]\nOutput: "aaaa"\nExplanation: lcp corresponds to any 4 letter string with a single distinct letter. The lexicographically smallest of them is "aaaa". \n
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Example 3:

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\nInput: lcp = [[4,3,2,1],[3,3,2,1],[2,2,2,1],[1,1,1,3]]\nOutput: ""\nExplanation: lcp[3][3] cannot be equal to 3 since word[3,...,3] consists of only a single letter; Thus, no answer exists.\n
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Constraints:

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

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Compiled with gcc 8.2 using the gnu11 standard.

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

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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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Go 1.21

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Python 3.10.

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Scala 2.13.7.

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Kotlin 1.9.0.

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Rust 1.58.1

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PHP 8.1.

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With bcmath module

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TypeScript 5.1.6, Node.js 16.13.2.

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