LeetCode 3103: Find Trending Hashtags II Solution

Master LeetCode problem 3103 (Find Trending Hashtags II ), a hard challenge, with our optimized solutions in Java, C++, and Python. Explore detailed explanations, test your code in our interactive editor, and prepare for coding interviews.

3103. Find Trending Hashtags II

Hard

Database

Problem Explanation

Explanation:

To solve this problem, we can use a priority queue to keep track of the trending hashtags based on their frequency. We can iterate through the given list of hashtags and update the frequency of each hashtag in a hashmap. Then, we can add each hashtag to the priority queue based on its frequency. Finally, we can pop the top k hashtags from the priority queue to get the trending hashtags.

Algorithm:

Initialize a hashmap to store the frequency of each hashtag.
Iterate through the list of hashtags and update the frequency in the hashmap.
Initialize a priority queue (max heap) to store the hashtags based on their frequency.
Add each hashtag to the priority queue based on its frequency.
Pop the top k hashtags from the priority queue to get the trending hashtags.

Time Complexity:
The time complexity of this approach is O(n log k), where n is the number of hashtags and k is the number of trending hashtags required.

Space Complexity:
The space complexity is O(n) to store the hashmap of hashtag frequencies and the priority queue.

Solution Code

import java.util.*;

class Solution {
    public List<String> findTrendingHashtags(List<String> hashtags, int k) {
        Map<String, Integer> freqMap = new HashMap<>();
        for (String hashtag : hashtags) {
            freqMap.put(hashtag, freqMap.getOrDefault(hashtag, 0) + 1);
        }

        PriorityQueue<String> pq = new PriorityQueue<>((a, b) -> freqMap.get(b) - freqMap.get(a));
        pq.addAll(freqMap.keySet());

        List<String> trending = new ArrayList<>();
        for (int i = 0; i < k && !pq.isEmpty(); i++) {
            trending.add(pq.poll());
        }

        return trending;
    }
}

Try It Yourself

Loading code editor...

Frequently Asked Questions

How to solve LeetCode 3103 (Find Trending Hashtags II )?

This page provides optimized solutions for LeetCode problem 3103 (Find Trending Hashtags II ) in Java, C++, and Python, along with a detailed explanation and an interactive code editor to test your code.

What is the time complexity of LeetCode 3103 (Find Trending Hashtags II )?

The time complexity for LeetCode 3103 (Find Trending Hashtags II ) varies by solution. Check the detailed explanation section for specific complexities in Java, C++, and Python implementations.

Can I run code for LeetCode 3103 on DevExCode?

Yes, DevExCode provides an interactive code editor where you can write, test, and run your code for LeetCode 3103 in Java, C++, or Python.

Back to LeetCode Solutions