{ "data": { "question": { "questionId": "3686", "questionFrontendId": "3388", "boundTopicId": null, "title": "Count Beautiful Splits in an Array", "titleSlug": "count-beautiful-splits-in-an-array", "content": "

You are given an array nums.

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A split of an array nums is beautiful if:

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    \n\t
  1. The array nums is split into three subarrays: nums1, nums2, and nums3, such that nums can be formed by concatenating nums1, nums2, and nums3 in that order.
  2. \n\t
  3. The subarray nums1 is a prefix of nums2 OR nums2 is a prefix of nums3.
  4. \n
\n\n

Return the number of ways you can make this split.

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Example 1:

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\n

Input: nums = [1,1,2,1]

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Output: 2

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Explanation:

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The beautiful splits are:

\n\n
    \n\t
  1. A split with nums1 = [1], nums2 = [1,2], nums3 = [1].
  2. \n\t
  3. A split with nums1 = [1], nums2 = [1], nums3 = [2,1].
  4. \n
\n
\n\n

Example 2:

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\n

Input: nums = [1,2,3,4]

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Output: 0

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Explanation:

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There are 0 beautiful splits.

\n
\n\n

 

\n

Constraints:

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

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OpenJDK 21. Using compile arguments: --enable-preview --release 21

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

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Python 2.7.18.

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

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C# 12 with .NET 8 runtime

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Node.js 20.10.0.

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Your code is run with --harmony flag, enabling new ES6 features.

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lodash.js library is included by default.

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Ruby 3.2

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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 5.10.

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You may use swift-algorithms 1.2.0 and swift-collections 1.1.4.

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Go 1.23

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Python 3.11.

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Scala 3.3.1.

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Kotlin 1.9.0.

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Rust 1.79.0. Your code will be compiled with opt-level 2.

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Supports rand v0.8 and regex\\u00a0v1 from crates.io

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PHP 8.2.

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With bcmath module

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TypeScript 5.1.6, Node.js 20.10.0.

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Compile Options: --alwaysStrict --strictBindCallApply --strictFunctionTypes --target ES2022

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Racket CS v8.15

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Using #lang racket

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Required data/gvector data/queue data/order data/heap automatically for your convenience

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Dart 3.2. You may use package collection

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Your code will be run directly without compiling

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