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Add TypeScript code and docs to Chapter of Heap (#349)

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* Add TypeScript code and docs to Chapter of Heap

* Update my_heap.ts

---------

Co-authored-by: Yudong Jin <krahets@163.com>
This commit is contained in:
Justin Tse
2023-02-07 20:50:54 +08:00
committed by GitHub
parent 7666632d0c
commit 1cc9cecebe
3 changed files with 266 additions and 6 deletions
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90
docs/chapter_heap/heap.md
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@ -214,7 +214,7 @@ comments: true
=== "TypeScript"
```typescript title="heap.ts"
// TypeScript 未提供内置堆 Heap 类
```
=== "C"
@ -361,7 +361,31 @@ comments: true
=== "TypeScript"
```typescript title="my_heap.ts"
private maxHeap: number[];
/* 构造函数，建立空堆或根据输入列表建堆 */
constructor(nums?: number[]) {
// 将列表元素原封不动添加进堆
this.maxHeap = nums === undefined ? [] : [...nums];
// 堆化除叶结点以外的其他所有结点
for (let i = this.parent(this.size() - 1); i >= 0; i--) {
this.siftDown(i);
}
}
/* 获取左子结点索引 */
private left(i: number): number {
return 2 * i + 1;
}
/* 获取右子结点索引 */
private right(i: number): number {
return 2 * i + 2;
}
/* 获取父结点索引 */
private parent(i: number): number {
return Math.floor((i - 1) / 2); // 向下整除
}
```
=== "C"
@ -454,7 +478,10 @@ comments: true
=== "TypeScript"
```typescript title="my_heap.ts"
/* 访问堆顶元素 */
public peek(): number {
return this.maxHeap[0];
}
```
=== "C"
@ -608,7 +635,27 @@ comments: true
=== "TypeScript"
```typescript title="my_heap.ts"
/* 元素入堆 */
public push(val: number): void {
// 添加结点
this.maxHeap.push(val);
// 从底至顶堆化
this.siftUp(this.size() - 1);
}
/* 从结点 i 开始，从底至顶堆化 */
private siftUp(i: number): void {
while (true) {
// 获取结点 i 的父结点
const p = this.parent(i);
// 当“越过根结点”或“结点无需修复”时，结束堆化
if (p < 0 || this.maxHeap[i] <= this.maxHeap[p]) break;
// 交换两结点
this.swap(i, p);
// 循环向上堆化
i = p;
}
}
```
=== "C"
@ -836,7 +883,36 @@ comments: true
=== "TypeScript"
```typescript title="my_heap.ts"
/* 元素出堆 */
public poll(): number {
// 判空处理
if (this.isEmpty()) throw new RangeError("Heap is empty.");
// 交换根结点与最右叶结点（即交换首元素与尾元素）
this.swap(0, this.size() - 1);
// 删除结点
const val = this.maxHeap.pop();
// 从顶至底堆化
this.siftDown(0);
// 返回堆顶元素
return val;
}
/* 从结点 i 开始，从顶至底堆化 */
private siftDown(i: number): void {
while (true) {
// 判断结点 i, l, r 中值最大的结点，记为 ma
const l = this.left(i), r = this.right(i);
let ma = i;
if (l < this.size() && this.maxHeap[l] > this.maxHeap[ma]) ma = l;
if (r < this.size() && this.maxHeap[r] > this.maxHeap[ma]) ma = r;
// 若结点 i 最大或索引 l, r 越界，则无需继续堆化，跳出
if (ma == i) break;
// 交换两结点
this.swap(i, ma);
// 循环向下堆化
i = ma;
}
}
```
=== "C"
@ -966,7 +1042,15 @@ comments: true
=== "TypeScript"
```typescript title="my_heap.ts"
/* 构造函数，建立空堆或根据输入列表建堆 */
constructor(nums?: number[]) {
// 将列表元素原封不动添加进堆
this.maxHeap = nums === undefined ? [] : [...nums];
// 堆化除叶结点以外的其他所有结点
for (let i = this.parent(this.size() - 1); i >= 0; i--) {
this.siftDown(i);
}
}
```
=== "C"