36 lines
753 B
JavaScript
36 lines
753 B
JavaScript
/*
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* @lc app=leetcode id=347 lang=javascript
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*
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* [347] Top K Frequent Elements
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*/
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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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// 这个算法的瓶颈在于排序算法，时间复杂度基本上是O(nlogn) 空间复杂度是O(n)
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const hashtable = {};
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const n = nums.length;
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const res = [];
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for (let i = 0; i < n; i++) {
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const num = nums[i];
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if (hashtable[num] !== void 0) {
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hashtable[num + ""] += 1;
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} else {
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hashtable[num + ""] = 1;
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}
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}
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// sort desc
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const list = Object.entries(hashtable);
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list.sort(([, countA], [, countB]) => countB - countA);
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for (let i = 0; i < k; i++) {
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res.push(list[i][0]);
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}
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return res;
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};
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