You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
50 lines
1.1 KiB
50 lines
1.1 KiB
8 months ago
|
// File: binary_search_insertion.go
|
||
|
|
// Created Time: 2023-08-23
|
||
|
|
// Author: Reanon (793584285@qq.com)
|
||
|
|
|
||
|
|
package chapter_searching
|
||
|
|
|
||
|
|
/* 二分搜尋插入點（無重複元素） */
|
||
|
|
func binarySearchInsertionSimple(nums []int, target int) int {
|
||
|
|
// 初始化雙閉區間 [0, n-1]
|
||
|
|
i, j := 0, len(nums)-1
|
||
|
|
for i <= j {
|
||
|
|
// 計算中點索引 m
|
||
|
|
m := i + (j-i)/2
|
||
|
|
if nums[m] < target {
|
||
|
|
// target 在區間 [m+1, j] 中
|
||
|
|
i = m + 1
|
||
|
|
} else if nums[m] > target {
|
||
|
|
// target 在區間 [i, m-1] 中
|
||
|
|
j = m - 1
|
||
|
|
} else {
|
||
|
|
// 找到 target ，返回插入點 m
|
||
|
|
return m
|
||
|
|
}
|
||
|
|
}
|
||
|
|
// 未找到 target ，返回插入點 i
|
||
|
|
return i
|
||
|
|
}
|
||
|
|
|
||
|
|
/* 二分搜尋插入點（存在重複元素） */
|
||
|
|
func binarySearchInsertion(nums []int, target int) int {
|
||
|
|
// 初始化雙閉區間 [0, n-1]
|
||
|
|
i, j := 0, len(nums)-1
|
||
|
|
for i <= j {
|
||
|
|
// 計算中點索引 m
|
||
|
|
m := i + (j-i)/2
|
||
|
|
if nums[m] < target {
|
||
|
|
// target 在區間 [m+1, j] 中
|
||
|
|
i = m + 1
|
||
|
|
} else if nums[m] > target {
|
||
|
|
// target 在區間 [i, m-1] 中
|
||
|
|
j = m - 1
|
||
|
|
} else {
|
||
|
|
// 首個小於 target 的元素在區間 [i, m-1] 中
|
||
|
|
j = m - 1
|
||
|
|
}
|
||
|
|
}
|
||
|
|
// 返回插入點 i
|
||
|
|
return i
|
||
|
|
}
|