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38 lines
923 B
Python
38 lines
923 B
Python
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"""
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File: top_k.py
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Created Time: 2023-06-10
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Author: Krahets (krahets@163.com)
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"""
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import sys, os.path as osp
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sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
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from modules import *
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import heapq
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def top_k_heap(nums: list[int], k: int) -> list[int]:
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"""基于堆查找数组中最大的 k 个元素"""
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heap = []
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# 将数组的前 k 个元素入堆
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for i in range(k):
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heapq.heappush(heap, nums[i])
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# 从第 k+1 个元素开始，保持堆的长度为 k
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for i in range(k, len(nums)):
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# 若当前元素大于堆顶元素，则将堆顶元素出堆、当前元素入堆
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if nums[i] > heap[0]:
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heapq.heappop(heap)
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heapq.heappush(heap, nums[i])
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return heap
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"""Driver Code"""
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if __name__ == "__main__":
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nums = [1, 7, 6, 3, 2]
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k = 3
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res = top_k_heap(nums, k)
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print(f"最大的 {k} 个元素为")
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print_heap(res)
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