From 95bc0ffdb2f82f32aee77ef0de8f0d9b3633cf4e Mon Sep 17 00:00:00 2001
From: Night Cruising <77157236+night-cruise@users.noreply.github.com>
Date: Thu, 31 Aug 2023 02:36:06 +0800
Subject: [PATCH] Feat: add rust codes for chapter searching (#710)

---
 codes/rust/Cargo.toml                         |  5 ++
 .../chapter_searching/binary_search_edge.rs   | 51 +++++++++++++++
 .../binary_search_insertion.rs                | 62 +++++++++++++++++++
 3 files changed, 118 insertions(+)
 create mode 100644 codes/rust/chapter_searching/binary_search_edge.rs
 create mode 100644 codes/rust/chapter_searching/binary_search_insertion.rs

diff --git a/codes/rust/Cargo.toml b/codes/rust/Cargo.toml
index 1b311391f..c2978fde0 100644
--- a/codes/rust/Cargo.toml
+++ b/codes/rust/Cargo.toml
@@ -114,6 +114,11 @@ path = "chapter_searching/binary_search.rs"
 name = "binary_search_edge"
 path = "chapter_searching/binary_search_edge.rs"
 
+# Run Command: cargo run --bin binary_search_insertion
+[[bin]]
+name = "binary_search_insertion"
+path = "chapter_searching/binary_search_insertion.rs"
+
 # Run Command: cargo run --bin bubble_sort
 [[bin]]
 name = "bubble_sort"
diff --git a/codes/rust/chapter_searching/binary_search_edge.rs b/codes/rust/chapter_searching/binary_search_edge.rs
new file mode 100644
index 000000000..e5baede9f
--- /dev/null
+++ b/codes/rust/chapter_searching/binary_search_edge.rs
@@ -0,0 +1,51 @@
+/*
+ * File: binary_search_edge.rs
+ * Created Time: 2023-08-30
+ * Author: night-cruise (2586447362@qq.com)
+ */
+
+mod binary_search_insertion;
+
+use binary_search_insertion::binary_search_insertion;
+
+
+/* 二分查找最左一个 target */
+fn binary_search_left_edge(nums: &[i32], target: i32) -> i32 {
+    // 等价于查找 target 的插入点
+    let i = binary_search_insertion(nums, target);
+    // 未找到 target ，返回 -1
+    if i == nums.len() as i32 || nums[i as usize] != target {
+        return -1;
+    }
+    // 找到 target ，返回索引 i
+    i
+}
+
+/* 二分查找最右一个 target */
+fn binary_search_right_edge(nums: &[i32], target: i32) -> i32 {
+    // 转化为查找最左一个 target + 1
+    let i = binary_search_insertion(nums, target + 1);
+    // j 指向最右一个 target ，i 指向首个大于 target 的元素
+    let j = i - 1;
+    // 未找到 target ，返回 -1
+    if j == -1 || nums[j as usize] != target {
+        return -1;
+    }
+    // 找到 target ，返回索引 j
+    j
+}
+
+/* Driver Code */
+fn main() {
+    // 包含重复元素的数组
+    let nums = [1, 3, 6, 6, 6, 6, 6, 10, 12, 15];
+    println!("\n数组 nums = {:?}", nums);
+
+    // 二分查找左边界和右边界
+    for target in [6, 7] {
+        let index = binary_search_left_edge(&nums, target);
+        println!("最左一个元素 {} 的索引为 {}", target, index);
+        let index = binary_search_right_edge(&nums, target);
+        println!("最右一个元素 {} 的索引为 {}", target, index);
+    }
+} 
\ No newline at end of file
diff --git a/codes/rust/chapter_searching/binary_search_insertion.rs b/codes/rust/chapter_searching/binary_search_insertion.rs
new file mode 100644
index 000000000..654b63f42
--- /dev/null
+++ b/codes/rust/chapter_searching/binary_search_insertion.rs
@@ -0,0 +1,62 @@
+/*
+ * File: binary_search_insertion.rs
+ * Created Time: 2023-08-30
+ * Author: night-cruise (2586447362@qq.com)
+ */
+#![allow(unused)]
+
+/* 二分查找插入点（无重复元素） */
+fn binary_search_insertion_simple(nums: &[i32], target: i32) -> i32 {
+    let (mut i, mut j) = (0, 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 {
+            return m;
+        }
+    }
+    // 未找到 target ，返回插入点 i
+    i
+}
+
+/* 二分查找插入点（存在重复元素） */
+pub fn binary_search_insertion(nums: &[i32], target: i32) -> i32 {
+    let (mut i, mut j) = (0, 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
+        }
+    }
+    // 返回插入点 i
+    i
+}
+
+
+/* Driver Code */
+fn main() {
+    // 无重复元素的数组
+    let nums = [1, 3, 6, 8, 12, 15, 23, 26, 31, 35];
+    println!("\n数组 nums = {:?}", nums);
+    // 二分查找插入点
+    for target in [6, 9] {
+        let index = binary_search_insertion_simple(&nums, target);
+        println!("元素 {} 的插入点的索引为 {}", target, index);
+    }
+
+    // 包含重复元素的数组
+    let nums = [1, 3, 6, 6, 6, 6, 6, 10, 12, 15];
+    println!("\n数组 nums = {:?}", nums);
+    // 二分查找插入点
+    for target in [2, 6, 20] {
+        let index = binary_search_insertion(&nums, target);
+        println!("元素 {} 的插入点的索引为 {}", target, index);
+    }
+}
\ No newline at end of file