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54 lines
1.4 KiB
Plaintext
54 lines
1.4 KiB
Plaintext
---
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title: LC-347
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description: Top K Frequent Elements
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---
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## Examples
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| Input | Output |
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| ---------------------------------- | -------- |
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| `nums = [1,1,1,2,2,3], k = 2` | `[1,2]` |
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| `nums = [1], k = 1` | `[1]` |
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| `nums = [1,2,1,2,1,2,3,1,3,2], k = 2` | `[1,2]` |
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## Hints
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<Accordion type="single">
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<AccordionItem title="Constraints">
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Constraints:
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• `1 <= nums.length <= 10^5`
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• `-10^4 <= nums[i] <= 10^4`
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• `k` is in the range `[1, the number of unique elements in the array]`
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• It is guaranteed that the answer is unique.
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</AccordionItem>
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<AccordionItem title="Problem Statement">
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Given an integer array nums and an integer `k`, return the `k` most frequent elements.
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You may return the answer in any order.
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Follow up: Your algorithm's time complexity must be better than `O(n log n)`, where n is the array's size.
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</AccordionItem>
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</Accordion>
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## Solution
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```js
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/**
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* @param {number[]} nums
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* @param {number} k
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* @return {number[]}
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*/
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var topKFrequent = function (nums, k) {
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// Default for Hammer
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const freq = {};
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for (let n of nums) freq[n] = (freq[n] || 0) + 1;
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// Problem Specific
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// Sort unique values by descending frequency, take the first k
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return Object.keys(freq)
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.map(Number)
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.sort((a, b) => freq[b] - freq[a])
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.slice(0, k);
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};
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```
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