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fceea4bbda
* fix: remove binary_search_edge * feat: add Swift codes for binary_search_insertion article * feat: add Swift codes for binary_search_edge article
67 lines
2.1 KiB
Swift
67 lines
2.1 KiB
Swift
/**
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* File: binary_search_insertion.swift
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* Created Time: 2023-08-06
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* Author: nuomi1 (nuomi1@qq.com)
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*/
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/* 二分查找插入点（无重复元素） */
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func binarySearchInsertionSimple(nums: [Int], target: Int) -> Int {
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var i = 0, j = nums.count - 1 // 初始化双闭区间 [0, n-1]
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while i <= j {
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let m = i + (j - i) / 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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return m // 找到 target ，返回插入点 m
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}
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}
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// 未找到 target ，返回插入点 i
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return i
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}
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/* 二分查找插入点（存在重复元素） */
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public func binarySearchInsertion(nums: [Int], target: Int) -> Int {
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var i = 0, j = nums.count - 1 // 初始化双闭区间 [0, n-1]
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while i <= j {
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let m = i + (j - i) / 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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// 返回插入点 i
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return i
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}
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#if !TARGET
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@main
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enum BinarySearchInsertion {
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/* Driver Code */
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static func main() {
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// 无重复元素的数组
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var nums = [1, 3, 6, 8, 12, 15, 23, 26, 31, 35]
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print("\n数组 nums = \(nums)")
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// 二分查找插入点
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for target in [6, 9] {
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let index = binarySearchInsertionSimple(nums: nums, target: target)
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print("元素 \(target) 的插入点的索引为 \(index)")
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}
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// 包含重复元素的数组
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nums = [1, 3, 6, 6, 6, 6, 6, 10, 12, 15]
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print("\n数组 nums = \(nums)")
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// 二分查找插入点
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for target in [2, 6, 20] {
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let index = binarySearchInsertion(nums: nums, target: target)
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print("元素 \(target) 的插入点的索引为 \(index)")
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}
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}
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}
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#endif
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