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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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55
codes/javascript/chapter_searching/binary_search_edge.js
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55
codes/javascript/chapter_searching/binary_search_edge.js
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/**
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* File: binary_search_edge.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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/* 二分查找最左一个元素 */
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function binary_search_left_edge(nums, target) {
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let i = 0, j = nums.length - 1; // 初始化双闭区间 [0, n-1]
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while (i <= j) {
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let m = Math.floor((i + j) / 2); // 计算中点索引 m
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if (nums[m] < target) {
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i = m + 1; // target 在区间 [m+1, j] 中
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} else if (nums[m] > target) {
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j = m - 1; // target 在区间 [i, m-1] 中
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} else {
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j = m - 1; // 首个小于 target 的元素在区间 [i, m-1] 中
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}
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}
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if (i == nums.length || nums[i] != target) {
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return -1; // 未找到目标元素,返回 -1
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}
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return i;
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}
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/* 二分查找最右一个元素 */
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function binary_search_right_edge(nums, target) {
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let i = 0, j = nums.length - 1; // 初始化双闭区间 [0, n-1]
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while (i <= j) {
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let m = Math.floor((i + j) / 2); // 计算中点索引 m
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if (nums[m] < target) {
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i = m + 1; // target 在区间 [m+1, j] 中
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} else if (nums[m] > target) {
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j = m - 1; // target 在区间 [i, m-1] 中
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} else {
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i = m + 1; // 首个大于 target 的元素在区间 [m+1, j] 中
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}
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}
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if (j == nums.length || nums[j] != target) {
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return -1; // 未找到目标元素,返回 -1
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}
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return j;
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}
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/* Driver Code */
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let target = 6;
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const nums = [1, 3, 6, 6, 6, 6, 6, 10, 12, 15];
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// 二分查找最左一个元素
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let index_left = binary_search_left_edge(nums, target);
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console.log("数组中最左一个元素 6 的索引 = ", index_left);
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// 二分查找最右一个元素
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let index_right = binary_search_right_edge(nums, target);
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console.log("数组中最右一个元素 6 的索引 = ", index_right);
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