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Fix binary_search_tree TS code and update JS code style (#715)

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* Fix binary_search_tree TS code

* Update binary_search_tree js code style

* Update binary_search_tree.ts

* Update avl_tree.ts

* Update binary_search_tree.ts

---------

Co-authored-by: Yudong Jin <krahets@163.com>
pull/718/head^2
Justin Tse 1 year ago committed by GitHub
parent 22d1135e04
commit 89a5f4d0d7
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 105 additions and 126 deletions
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6
codes/javascript/chapter_tree/binary_search_tree.js
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@ -56,7 +56,7 @@ class BinarySearchTree {
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;
}
@ -82,7 +82,7 @@ class BinarySearchTree {
// 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;
@ -119,7 +119,7 @@ console.log('\n初始化的二叉树为\n');
printTree(bst.getRoot());
/* 查找节点 */
let node = bst.search(7);
const node = bst.search(7);
console.log('\n查找到的节点对象为 ' + node + '，节点值 = ' + node.val);
/* 插入节点 */

2
codes/typescript/chapter_tree/avl_tree.ts
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@ -218,3 +218,5 @@ testRemove(avlTree, 4); // 删除度为 2 的节点
/* 查询节点 */
const node = avlTree.search(7);
console.log('\n查找到的节点对象为', node, '，节点值 = ' + node.val);
export {};

155
codes/typescript/chapter_tree/binary_search_tree.ts
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@ -8,159 +8,136 @@ import { TreeNode } from '../modules/TreeNode';
import { printTree } from '../modules/PrintUtil';
/* 二叉搜索树 */
let root: TreeNode | null;
class BinarySearchTree {
private root: TreeNode | null;
function BinarySearchTree(nums: number[]): void {
nums.sort((a, b) => a - b); // 排序数组
root = buildTree(nums, 0, nums.length - 1); // 构建二叉搜索树
/* 构造方法 */
constructor() {
// 初始化空树
this.root = null;
}
/* 获取二叉树根节点 */
function getRoot(): TreeNode | null {
return root;
}
/* 构建二叉搜索树 */
function buildTree(nums: number[], i: number, j: number): TreeNode | null {
if (i > j) {
return null;
}
// 将数组中间节点作为根节点
let mid = Math.floor((i + j) / 2);
let root = new TreeNode(nums[mid]);
// 递归建立左子树和右子树
root.left = buildTree(nums, i, mid - 1);
root.right = buildTree(nums, mid + 1, j);
return root;
getRoot(): TreeNode | null {
return this.root;
}
/* 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;
}
/* 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;
}
/* 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;
}
}
}
/* Driver Code */
/* 初始化二叉搜索树 */
const nums = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
BinarySearchTree(nums);
const bst = new BinarySearchTree();
// 请注意，不同的插入顺序会生成不同的二叉树，该序列可以生成一个完美二叉树
const nums = [8, 4, 12, 2, 6, 10, 14, 1, 3, 5, 7, 9, 11, 13, 15];
for (const num of nums) {
bst.insert(num);
}
console.log('\n初始化的二叉树为\n');
printTree(getRoot());
printTree(bst.getRoot());
/* 查找节点 */
let node = search(7);
console.log('\n查找到的节点对象为 ' + node + '，节点值 = ' + node!.val);
const node = bst.search(7);
console.log('\n查找到的节点对象为 ' + node + '，节点值 = ' + (node ? node.val : 'null'));
/* 插入节点 */
insert(16);
bst.insert(16);
console.log('\n插入节点 16 后，二叉树为\n');
printTree(getRoot());
printTree(bst.getRoot());
/* 删除节点 */
remove(1);
bst.remove(1);
console.log('\n删除节点 1 后，二叉树为\n');
printTree(getRoot());
remove(2);
printTree(bst.getRoot());
bst.remove(2);
console.log('\n删除节点 2 后，二叉树为\n');
printTree(getRoot());
remove(4);
printTree(bst.getRoot());
bst.remove(4);
console.log('\n删除节点 4 后，二叉树为\n');
printTree(getRoot());
printTree(bst.getRoot());
export {};

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