This commit is contained in:
krahets
2023-10-29 20:01:26 +08:00
parent 368cbf4261
commit 7b7e1b7c8b
4 changed files with 326 additions and 312 deletions

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@@ -259,33 +259,49 @@ comments: true
=== "TS"
```typescript title="top_k.ts"
[class]{}-[func]{pushMinHeap}
/* 元素入堆 */
function pushMinHeap(maxHeap: MaxHeap, val: number): void {
// 元素取反
maxHeap.push(-val);
}
[class]{}-[func]{popMinHeap}
/* 元素出堆 */
function popMinHeap(maxHeap: MaxHeap): number {
// 元素取反
return -maxHeap.pop();
}
[class]{}-[func]{peekMinHeap}
/* 访问堆顶元素 */
function peekMinHeap(maxHeap: MaxHeap): number {
// 元素取反
return -maxHeap.peek();
}
[class]{}-[func]{getMinHeap}
/* 取出堆中元素 */
function getMinHeap(maxHeap: MaxHeap): number[] {
// 元素取反
return maxHeap.getMaxHeap().map((num: number) => -num);
}
/* 基于堆查找数组中最大的 k 个元素 */
function topKHeap(nums: number[], k: number): number[] {
// 将堆中所有元素取反,从而用大顶堆来模拟小顶堆
const invertedNums = nums.map((num) => -num);
// 初始化小顶堆
// 请注意:我们将堆中所有元素取反,从而用大顶堆来模拟小顶堆
const maxHeap = new MaxHeap([]);
// 将数组的前 k 个元素入堆
const heap = new MaxHeap(invertedNums.slice(0, k));
for (let i = 0; i < k; i++) {
pushMinHeap(maxHeap, nums[i]);
}
// 从第 k+1 个元素开始,保持堆的长度为 k
for (let i = k; i < invertedNums.length; i++) {
// 若当前元素于堆顶元素,则将堆顶元素出堆、当前元素入堆
if (invertedNums[i] < heap.peek()) {
heap.pop();
heap.push(invertedNums[i]);
for (let i = k; i < nums.length; i++) {
// 若当前元素于堆顶元素,则将堆顶元素出堆、当前元素入堆
if (nums[i] > peekMinHeap(maxHeap)) {
popMinHeap(maxHeap);
pushMinHeap(maxHeap, nums[i]);
}
}
// 取出堆中元素
const maxHeap = heap.getMaxHeap();
// 对堆中元素取相反数
const invertedMaxHeap = maxHeap.map((num) => -num);
return invertedMaxHeap;
// 返回堆中元素
return getMinHeap(maxHeap);
}
```