You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
39 lines
1.1 KiB
39 lines
1.1 KiB
/*
|
|
* File: top_k.rs
|
|
* Created Time: 2023-07-16
|
|
* Author: night-cruise (2586447362@qq.com)
|
|
*/
|
|
|
|
include!("../include/include.rs");
|
|
|
|
use std::cmp::Reverse;
|
|
use std::collections::BinaryHeap;
|
|
|
|
/* 基于堆查找数组中最大的 k 个元素 */
|
|
fn top_k_heap(nums: Vec<i32>, k: usize) -> BinaryHeap<Reverse<i32>> {
|
|
// BinaryHeap 是大顶堆，使用 Reverse 将元素取反，从而实现小顶堆
|
|
let mut heap = BinaryHeap::<Reverse<i32>>::new();
|
|
// 将数组的前 k 个元素入堆
|
|
for &num in nums.iter().take(k) {
|
|
heap.push(Reverse(num));
|
|
}
|
|
// 从第 k+1 个元素开始，保持堆的长度为 k
|
|
for &num in nums.iter().skip(k) {
|
|
// 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
|
|
if num > heap.peek().unwrap().0 {
|
|
heap.pop();
|
|
heap.push(Reverse(num));
|
|
}
|
|
}
|
|
heap
|
|
}
|
|
|
|
/* Driver Code */
|
|
fn main() {
|
|
let nums = vec![1, 7, 6, 3, 2];
|
|
let k = 3;
|
|
|
|
let res = top_k_heap(nums, k);
|
|
println!("最大的 {} 个元素为", k);
|
|
print_util::print_heap(res.into_iter().map(|item| item.0).collect());
|
|
} |