{ "data": { "question": { "questionId": "2888", "questionFrontendId": "2780", "boundTopicId": null, "title": "Minimum Index of a Valid Split", "titleSlug": "minimum-index-of-a-valid-split", "content": "

An element x of an integer array arr of length m is dominant if freq(x) * 2 > m, where freq(x) is the number of occurrences of x in arr. Note that this definition implies that arr can have at most one dominant element.

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You are given a 0-indexed integer array nums of length n with one dominant element.

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You can split nums at an index i into two arrays nums[0, ..., i] and nums[i + 1, ..., n - 1], but the split is only valid if:

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Here, nums[i, ..., j] denotes the subarray of nums starting at index i and ending at index j, both ends being inclusive. Particularly, if j < i then nums[i, ..., j] denotes an empty subarray.

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Return the minimum index of a valid split. If no valid split exists, return -1.

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Example 1:

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\nInput: nums = [1,2,2,2]\nOutput: 2\nExplanation: We can split the array at index 2 to obtain arrays [1,2,2] and [2]. \nIn array [1,2,2], element 2 is dominant since it occurs twice in the array and 2 * 2 > 3. \nIn array [2], element 2 is dominant since it occurs once in the array and 1 * 2 > 1.\nBoth [1,2,2] and [2] have the same dominant element as nums, so this is a valid split. \nIt can be shown that index 2 is the minimum index of a valid split. 
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Example 2:

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\nInput: nums = [2,1,3,1,1,1,7,1,2,1]\nOutput: 4\nExplanation: We can split the array at index 4 to obtain arrays [2,1,3,1,1] and [1,7,1,2,1].\nIn array [2,1,3,1,1], element 1 is dominant since it occurs thrice in the array and 3 * 2 > 5.\nIn array [1,7,1,2,1], element 1 is dominant since it occurs thrice in the array and 3 * 2 > 5.\nBoth [2,1,3,1,1] and [1,7,1,2,1] have the same dominant element as nums, so this is a valid split.\nIt can be shown that index 4 is the minimum index of a valid split.
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Example 3:

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\nInput: nums = [3,3,3,3,7,2,2]\nOutput: -1\nExplanation: It can be shown that there is no valid split.\n
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Constraints:

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Compiled with clang 11 using the latest C++ 17 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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Most standard library headers are already included automatically for your convenience.

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For hash table operations, you may use uthash. \\\"uthash.h\\\" is included by default. Below are some examples:

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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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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 1.18

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Python 3.10.

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Scala 2.13.7.

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Kotlin 1.3.10.

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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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Run with Racket 8.3.

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