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krahets
2023-09-02 23:03:42 +08:00
parent 799698e67c
commit 503ca797b8
12 changed files with 314 additions and 91 deletions
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101
chapter_tree/binary_search_tree.md
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@@ -155,17 +155,16 @@ comments: true
```typescript title="binary_search_tree.ts"
/* 查找节点 */
function search(num: number): TreeNode | null {
let cur = root;
search(num: number): TreeNode | null {
let cur = this.root;
// 循环查找，越过叶节点后跳出
while (cur !== null) {
if (cur.val < num) {
cur = cur.right; // 目标节点在 cur 的右子树中
} else if (cur.val > num) {
cur = cur.left; // 目标节点在 cur 的左子树中
} else {
break; // 找到目标节点，跳出循环
}
// 目标节点在 cur 的右子树中
if (cur.val < num) cur = cur.right;
// 目标节点在 cur 的左子树中
else if (cur.val > num) cur = cur.left;
// 找到目标节点，跳出循环
else break;
}
// 返回目标节点
return cur;
@@ -489,7 +488,7 @@ comments: true
else cur = cur.left;
}
// 插入节点
let node = new TreeNode(num);
const node = new TreeNode(num);
if (pre.val < num) pre.right = node;
else pre.left = node;
}
@@ -499,33 +498,28 @@ comments: true
```typescript title="binary_search_tree.ts"
/* 插入节点 */
function insert(num: number): void {
insert(num: number): void {
// 若树为空，则初始化根节点
if (root === null) {
root = new TreeNode(num);
if (this.root === null) {
this.root = new TreeNode(num);
return;
}
let cur = root,
let cur: TreeNode | null = this.root,
pre: TreeNode | null = null;
// 循环查找，越过叶节点后跳出
while (cur !== null) {
if (cur.val === num) {
return; // 找到重复节点，直接返回
}
// 找到重复节点，直接返回
if (cur.val === num) return;
pre = cur;
if (cur.val < num) {
cur = cur.right as TreeNode; // 插入位置在 cur 的右子树中
} else {
cur = cur.left as TreeNode; // 插入位置在 cur 的左子树中
}
// 插入位置在 cur 的右子树中
if (cur.val < num) cur = cur.right;
// 插入位置在 cur 的左子树中
else cur = cur.left;
}
// 插入节点
let node = new TreeNode(num);
if (pre!.val < num) {
pre!.right = node;
} else {
pre!.left = node;
}
const node = new TreeNode(num);
if (pre!.val < num) pre!.right = node;
else pre!.left = node;
}
```
@@ -1044,7 +1038,7 @@ comments: true
// 子节点数量 = 0 or 1
if (cur.left === null || cur.right === null) {
// 当子节点数量 = 0 / 1 时， child = null / 该子节点
let child = cur.left !== null ? cur.left : cur.right;
const child = cur.left !== null ? cur.left : cur.right;
// 删除节点 cur
if (cur !== this.root) {
if (pre.left === cur) pre.left = child;
@@ -1073,57 +1067,48 @@ comments: true
```typescript title="binary_search_tree.ts"
/* 删除节点 */
function remove(num: number): void {
remove(num: number): void {
// 若树为空，直接提前返回
if (root === null) {
return;
}
let cur = root,
if (this.root === null) return;
let cur: TreeNode | null = this.root,
pre: TreeNode | null = null;
// 循环查找，越过叶节点后跳出
while (cur !== null) {
// 找到待删除节点，跳出循环
if (cur.val === num) {
break;
}
if (cur.val === num) break;
pre = cur;
if (cur.val < num) {
cur = cur.right as TreeNode; // 待删除节点在 cur 的右子树中
} else {
cur = cur.left as TreeNode; // 待删除节点在 cur 的左子树中
}
// 待删除节点在 cur 的右子树中
if (cur.val < num) cur = cur.right;
// 待删除节点在 cur 的左子树中
else cur = cur.left;
}
// 若无待删除节点，则直接返回
if (cur === null) {
return;
}
if (cur === null) return;
// 子节点数量 = 0 or 1
if (cur.left === null || cur.right === null) {
// 当子节点数量 = 0 / 1 时， child = null / 该子节点
let child = cur.left !== null ? cur.left : cur.right;
const child: TreeNode | null =
cur.left !== null ? cur.left : cur.right;
// 删除节点 cur
if (cur != root) {
if (pre!.left === cur) {
pre!.left = child;
} else {
pre!.right = child;
}
if (cur !== this.root) {
if (pre!.left === cur) pre!.left = child;
else pre!.right = child;
} else {
// 若删除节点为根节点，则重新指定根节点
root = child;
this.root = child;
}
}
// 子节点数量 = 2
else {
// 获取中序遍历中 cur 的下一个节点
let tmp = cur.right;
while (tmp.left !== null) {
tmp = tmp.left;
let tmp: TreeNode | null = cur.right;
while (tmp!.left !== null) {
tmp = tmp!.left;
}
// 递归删除节点 tmp
remove(tmp!.val);
this.remove(tmp!.val);
// 用 tmp 覆盖 cur
cur.val = tmp.val;
cur.val = tmp!.val;
}
}
```