{ "data": { "question": { "questionId": "3200", "questionFrontendId": "2930", "boundTopicId": null, "title": "Number of Strings Which Can Be Rearranged to Contain Substring", "titleSlug": "number-of-strings-which-can-be-rearranged-to-contain-substring", "content": "

You are given an integer n.

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A string s is called good if it contains only lowercase English characters and it is possible to rearrange the characters of s such that the new string contains "leet" as a substring.

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For example:

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Return the total number of good strings of length n.

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Since the answer may be large, return it modulo 109 + 7.

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A substring is a contiguous sequence of characters within a string.

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Example 1:

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\nInput: n = 4\nOutput: 12\nExplanation: The 12 strings which can be rearranged to have "leet" as a substring are: "eelt", "eetl", "elet", "elte", "etel", "etle", "leet", "lete", "ltee", "teel", "tele", and "tlee".\n
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Example 2:

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\nInput: n = 10\nOutput: 83943898\nExplanation: The number of strings with length 10 which can be rearranged to have "leet" as a substring is 526083947580. Hence the answer is 526083947580 % (109 + 7) = 83943898.\n
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Constraints:

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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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Includes Pair class from https://docs.oracle.com/javase/8/javafx/api/javafx/util/Pair.html.

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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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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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Dart 2.17.3

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