From 8347bc4aaab9d45e5aa8ae020f53530db3a43953 Mon Sep 17 00:00:00 2001
From: Xu Shaohua <shaohua@biofan.org>
Date: Wed, 22 May 2024 16:03:41 +0800
Subject: [PATCH] leetcode: Add 0912

---
 src/leetcode/0912.sort-an-array/Cargo.toml  |   7 +
 src/leetcode/0912.sort-an-array/index.md    |   4 +
 src/leetcode/0912.sort-an-array/src/main.rs | 147 ++++++++++++++++++++
 3 files changed, 158 insertions(+)
 create mode 100644 src/leetcode/0912.sort-an-array/Cargo.toml
 create mode 100644 src/leetcode/0912.sort-an-array/index.md
 create mode 100644 src/leetcode/0912.sort-an-array/src/main.rs

diff --git a/src/leetcode/0912.sort-an-array/Cargo.toml b/src/leetcode/0912.sort-an-array/Cargo.toml
new file mode 100644
index 000000000..fe9b57721
--- /dev/null
+++ b/src/leetcode/0912.sort-an-array/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "lc-0912-sort-an-array"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]
diff --git a/src/leetcode/0912.sort-an-array/index.md b/src/leetcode/0912.sort-an-array/index.md
new file mode 100644
index 000000000..77a618ba8
--- /dev/null
+++ b/src/leetcode/0912.sort-an-array/index.md
@@ -0,0 +1,4 @@
+
+# 
+
+[问题描述](../problems/)
diff --git a/src/leetcode/0912.sort-an-array/src/main.rs b/src/leetcode/0912.sort-an-array/src/main.rs
new file mode 100644
index 000000000..14d21c2d5
--- /dev/null
+++ b/src/leetcode/0912.sort-an-array/src/main.rs
@@ -0,0 +1,147 @@
+// Copyright (c) 2024 Xu Shaohua <shaohua@biofan.org>. All rights reserved.
+// Use of this source is governed by General Public License that can be found
+// in the LICENSE file.
+
+// Builtin sorting
+pub fn sort_array1(nums: Vec<i32>) -> Vec<i32> {
+    let mut nums = nums;
+    nums.sort_unstable();
+    nums
+}
+
+// Merge sort
+pub fn sort_array2(nums: Vec<i32>) -> Vec<i32> {
+    fn merge(left: &[i32], right: &[i32]) -> Vec<i32> {
+        let mut nums = Vec::with_capacity(left.len() + right.len());
+
+        let mut left_index = 0;
+        let mut right_index = 0;
+        // 同时遍历两个数组, 将较小的数放到 nums 数组.
+        while left_index < left.len() && right_index < right.len() {
+            if left[left_index] < right[right_index] {
+                nums.push(left[left_index]);
+                left_index += 1;
+            } else {
+                nums.push(right[right_index]);
+                right_index += 1;
+            }
+        }
+
+        // 如果 left 数组还有剩余, 就把它们都合并到 nums.
+        while left_index < left.len() {
+            nums.push(left[left_index]);
+            left_index += 1;
+        }
+
+        // 如果 right 数组还有剩余, 就把它们都合并到 nums.
+        while right_index < right.len() {
+            nums.push(right[right_index]);
+            right_index += 1;
+        }
+
+        nums
+    }
+
+    fn merge_sort(nums: &[i32]) -> Vec<i32> {
+        // 如果数组元素不超过 1 个, 就直接返回它
+        if nums.len() < 2 {
+            return nums.to_vec();
+        }
+
+        let middle = nums.len() / 2;
+        let left_nums = merge_sort(&nums[..middle]);
+        let right_nums = merge_sort(&nums[middle..]);
+        merge(&left_nums, &right_nums)
+    }
+
+    merge_sort(&nums)
+}
+
+// Quick sort
+// FIXME(Shaohua): Time out
+pub fn sort_array3(nums: Vec<i32>) -> Vec<i32> {
+    fn partition(nums: &mut [i32], low: usize, high: usize) -> usize {
+        // 选择左侧第一个元素为基数 pivot
+        let pivot = nums[low];
+
+        // 使用双指针法, 以 pivot 为基准, 重新排布数组中的元素, 大的在右边,
+        // 小的在左边
+
+        let mut left: usize = low;
+        let mut right: usize = high;
+        while left < right {
+            // 找到右侧第一个比 pivot 小的数
+            while left < right && nums[right] >= pivot {
+                right -= 1;
+            }
+
+            // 找到左侧第一个比 pivot 大的数
+            while left < right && nums[left] <= pivot {
+                left += 1;
+            }
+            nums.swap(left, right);
+        }
+
+        // 把基数放在中间合适的位置
+        nums.swap(left, low);
+
+        // 返回基数的索引位置
+        left
+    }
+
+    fn quick_sort(nums: &mut [i32], low: usize, high: usize) {
+        if low < high {
+            // 计算基数
+            let pivot: usize = partition(nums, low, high);
+            // 对左右两侧数组单独排序
+            if low + 1 < pivot {
+                quick_sort(nums, low, pivot - 1);
+            }
+            quick_sort(nums, pivot + 1, high);
+        }
+    }
+
+    if nums.is_empty() {
+        return nums;
+    }
+    let mut nums = nums;
+    let len = nums.len();
+    quick_sort(&mut nums, 0, len - 1);
+    nums
+}
+
+pub type SolutionFn = fn(Vec<i32>) -> Vec<i32>;
+
+fn check_solution(func: SolutionFn) {
+    let nums = vec![5, 2, 3, 1];
+    assert_eq!(func(nums), [1, 2, 3, 5]);
+
+    let nums = vec![5, 1, 1, 2, 0, 0];
+    assert_eq!(func(nums), [0, 0, 1, 1, 2, 5]);
+}
+
+fn main() {
+    check_solution(sort_array1);
+    check_solution(sort_array2);
+    check_solution(sort_array3);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{check_solution, sort_array1, sort_array2, sort_array3};
+
+    #[test]
+    fn test_sort_array1() {
+        check_solution(sort_array1);
+    }
+
+    #[test]
+    fn test_sort_array2() {
+        check_solution(sort_array2);
+    }
+
+    #[test]
+    fn test_sort_array3() {
+        check_solution(sort_array3);
+    }
+}