Keep the k largest values with a heap

Problem

Implement k_largest(xs, k) using heapq. Return the k largest values in descending order. For k <= 0, return []; if k exceeds the input length, return all values in descending order.

Starter code

def k_largest(xs, k):
    pass

Reveal answer or reference solution

import heapq
def k_largest(xs, k):
    if k <= 0:
        return []
    return sorted(heapq.nlargest(k, xs), reverse=True)

Public tests

k_largest([4,1,7,3,7], 3) → [7, 7, 4]
k_largest([2,1], 5) → [2, 1]
k_largest([2,1], 0) → []

Local history

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Data Structures Practice