Top K Frequent Elements in Java: Explanation & Practice

Problem summary

Given an array, find the k most frequently occurring elements.

Starter code

import java.util.*;

public class Main {
    public static void main(String[] args) {
        int[] nums = {1, 1, 1, 2, 2, 3};
        int k = 2;
        
        // Find top k frequent elements
        // Print space-separated
    }
}

Expected output and test cases

• Top 2 frequent

  1 2

• Top 1 frequent

  1

• All elements

  1 2 3

Hints

1. Count frequencies with HashMap
2. Use PriorityQueue or bucket sort
3. Return top k by frequency

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