Top K Frequent Elements

Problem

Return the k values that appear most often in nums.

Count frequencies with a dictionary, then order values by descending count and break ties by ascending value so the output is deterministic. Return an empty list when k is 0.

Hint

Sort by the tuple (negative frequency, value) for a stable, deterministic order.

Test cases

case 1

in: [[1,1,1,2,2,3],2]

expected: [1,2]

case 2

in: [[1],1]

expected: [1]

case 3

in: [[4,4,4,2,2,3,3,3],2]

expected: [3,4]

case 4

in: [[1,2,3],3]

expected: [1,2,3]

case 5

in: [[5,5],1]

expected: [5]

Starter codePython

def top_k_frequent(nums, k):
    # Your code here
    pass

5 test cases · run your code against them in the editor