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Add JavaScript and TypeScript code of heap sort, selection sort and binary search edge and Fix the indentation of TS code (#545)
* Fix the indentation of TS code * Add JavaScript and TypeScript code of heap sort, selection sort and binary search edge * Fix the style of JS and TS code
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49
codes/javascript/chapter_sorting/heap_sort.js
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49
codes/javascript/chapter_sorting/heap_sort.js
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/**
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* File: heap_sort.js
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* Created Time: 2023-06-04
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* Author: Justin (xiefahit@gmail.com)
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*/
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/* 堆的长度为 n ,从节点 i 开始,从顶至底堆化 */
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function sift_down(nums, n, i) {
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while (true) {
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// 判断节点 i, l, r 中值最大的节点,记为 ma
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let l = 2 * i + 1;
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let r = 2 * i + 2;
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let ma = i;
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if (l < n && nums[l] > nums[ma]) {
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ma = l;
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}
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if (r < n && nums[r] > nums[ma]) {
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ma = r;
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}
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// 若节点 i 最大或索引 l, r 越界,则无需继续堆化,跳出
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if (ma === i) {
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break;
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}
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// 交换两节点
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[nums[i], nums[ma]] = [nums[ma], nums[i]];
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// 循环向下堆化
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i = ma;
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}
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}
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/* 堆排序 */
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function heap_sort(nums) {
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// 建堆操作:堆化除叶节点以外的其他所有节点
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for (let i = Math.floor(nums.length / 2) - 1; i >= 0; i--) {
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sift_down(nums, nums.length, i);
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}
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// 从堆中提取最大元素,循环 n-1 轮
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for (let i = nums.length - 1; i > 0; i--) {
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// 交换根节点与最右叶节点(即交换首元素与尾元素)
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[nums[0], nums[i]] = [nums[i], nums[0]];
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// 以根节点为起点,从顶至底进行堆化
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sift_down(nums, i, 0);
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}
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}
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/* Driver Code */
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const nums = [4, 1, 3, 1, 5, 2];
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heap_sort(nums);
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console.log("堆排序完成后 nums =", nums);
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27
codes/javascript/chapter_sorting/selection_sort.js
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27
codes/javascript/chapter_sorting/selection_sort.js
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/**
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* File: selection_sort.js
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* Created Time: 2023-06-04
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* Author: Justin (xiefahit@gmail.com)
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*/
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/* 选择排序 */
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function selection_sort(nums) {
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let n = nums.length;
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// 外循环:未排序区间为 [i, n-1]
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for (let i = 0; i < n - 1; i++) {
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// 内循环:找到未排序区间内的最小元素
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let k = i;
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for (let j = i + 1; j < n; j++) {
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if (nums[j] < nums[k]) {
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k = j; // 记录最小元素的索引
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}
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}
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// 将该最小元素与未排序区间的首个元素交换
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[nums[i], nums[k]] = [nums[k], nums[i]];
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}
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}
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/* Driver Code */
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const nums = [4, 1, 3, 1, 5, 2];
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selection_sort(nums);
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console.log("选择排序完成后 nums =", nums);
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