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Add the section of binary search insertion. (#671)

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Refactor the section of binary search edge.
Finetune the figures of binary search.
This commit is contained in:
Yudong Jin
2023-08-04 05:16:56 +08:00
committed by GitHub
parent 3d81b2d954
commit 71074d88f6
52 changed files with 546 additions and 621 deletions
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59
codes/rust/chapter_searching/binary_search_edge.rs
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@@ -1,59 +0,0 @@
/*
* File: binary_search_edge.rs
* Created Time: 2023-05-31
* Author: WSL0809 (wslzzy@outlook.com)
*/
/* 二分查找最左一个元素 */
fn binary_search_left_edge(nums: &[i32], target: i32) -> i32 {
let mut i = 0;
let mut j = nums.len() as i32 - 1; // 初始化双闭区间 [0, n-1]
while i <= j {
let m = i + (j - i) / 2; // 计算中点索引 m
if nums[m as usize] < target {
i = m + 1; // target 在区间 [m+1, j] 中
} else if nums[m as usize] > target {
j = m - 1; // target 在区间 [i, m-1] 中
} else {
j = m - 1; // 首个小于 target 的元素在区间 [i, m-1] 中
}
}
if i == nums.len() as i32 || nums[i as usize] != target {
return -1; // 未找到目标元素，返回 -1
}
i
}
/* 二分查找最右一个元素 */
fn binary_search_right_edge(nums: &[i32], target: i32) -> i32 {
let mut i = 0;
let mut j = nums.len() as i32 - 1; // 初始化双闭区间 [0, n-1]
while i <= j {
let m = i + (j - i) / 2; // 计算中点索引 m
if nums[m as usize] < target {
i = m + 1; // target 在区间 [m+1, j] 中
} else if nums[m as usize] > target {
j = m - 1; // target 在区间 [i, m-1] 中
} else {
i = m + 1; // 首个大于 target 的元素在区间 [m+1, j] 中
}
}
if j < 0 || nums[j as usize] != target {
return -1; // 未找到目标元素，返回 -1
}
j
}
/* Driver Code */
pub fn main() {
let target = 6;
let nums = [1, 3, 6, 6, 6, 6, 6, 10, 12, 15];
// 二分查找最左一个元素
let index_left = binary_search_left_edge(&nums, target);
println!("数组中最左一个元素 6 的索引 = {}", index_left);
// 二分查找最右一个元素
let index_right = binary_search_right_edge(&nums, target);
println!("数组中最右一个元素 6 的索引 = {}", index_right);
}