https://suigetsu312.github.io/blog/tags/hashtable/Recent content in HashTable on mizu-blogHugo -- 0.157.0zh-twMon, 02 Mar 2026 00:35:15 +0800https://suigetsu312.github.io/blog/posts/topkfrequentelements/Mon, 02 Mar 2026 00:35:15 +0800https://suigetsu312.github.io/blog/posts/topkfrequentelements/<h1 id="topkfrequentelements">TopKFrequentElements</h1> <p><strong>Difficulty:</strong> Medium<br> <strong>Topics:</strong> Hash Table, Heap, Frequency Counting</p> <blockquote> <p>Given an integer array nums and an integer k, return the k most frequent elements. You may return the answer in any order.</p> </blockquote> <h2 id="approach">Approach</h2> <p>This problem asks us to find the k most frequent elements. We first use an <code>unordered_map</code> to count the frequency of each element. Then we use a <code>min-heap</code> of size k to maintain the current top-k elements. When the heap size exceeds k, we remove the smallest element. Finally, we obtain a list of size k that contains the top-k elements.</p>