mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-27 14:16:29 +08:00
40 lines
1 KiB
Python
40 lines
1 KiB
Python
|
"""
|
||
|
|
File: top_k.py
|
||
|
|
Created Time: 2023-06-10
|
||
|
|
Author: krahets (krahets@163.com)
|
||
|
|
"""
|
||
|
|
|
||
|
|
import sys
|
||
|
|
from pathlib import Path
|
||
|
|
|
||
|
|
sys.path.append(str(Path(__file__).parent.parent))
|
||
|
|
from modules import print_heap
|
||
|
|
|
||
|
|
import heapq
|
||
|
|
|
||
|
|
|
||
|
|
def top_k_heap(nums: list[int], k: int) -> list[int]:
|
||
|
|
"""Using heap to find the largest k elements in an array"""
|
||
|
|
# Initialize min-heap
|
||
|
|
heap = []
|
||
|
|
# Enter the first k elements of the array into the heap
|
||
|
|
for i in range(k):
|
||
|
|
heapq.heappush(heap, nums[i])
|
||
|
|
# From the k+1th element, keep the heap length as k
|
||
|
|
for i in range(k, len(nums)):
|
||
|
|
# If the current element is larger than the heap top element, remove the heap top element and enter the current element into the heap
|
||
|
|
if nums[i] > heap[0]:
|
||
|
|
heapq.heappop(heap)
|
||
|
|
heapq.heappush(heap, nums[i])
|
||
|
|
return heap
|
||
|
|
|
||
|
|
|
||
|
|
"""Driver Code"""
|
||
|
|
if __name__ == "__main__":
|
||
|
|
nums = [1, 7, 6, 3, 2]
|
||
|
|
k = 3
|
||
|
|
|
||
|
|
res = top_k_heap(nums, k)
|
||
|
|
print(f"The largest {k} elements are")
|
||
|
|
print_heap(res)
|