feat: add solutions to lcof problems

- 面试题37. 序列化二叉树
- 面试题38. 字符串的排列
- 面试题59 - I. 滑动窗口的最大值
- 面试题59 - II. 队列的最大值

Author: YangFong

lcof/面试题37. 序列化二叉树/README.md

@@ -170,6 +170,8 @@ public class Codec {
 
 ### **JavaScript**
 
+层序遍历：
+
 ```js
 /**
  * Definition for a binary tree node.
@@ -235,6 +237,59 @@ var deserialize = function (data) {
  */
 ```
 
+前序遍历：
+
+```js
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val) {
+ *     this.val = val;
+ *     this.left = this.right = null;
+ * }
+ */
+
+/**
+ * Encodes a tree to a single string.
+ *
+ * @param {TreeNode} root
+ * @return {string}
+ */
+var serialize = function (root) {
+    if (root == null) {
+        return '#';
+    }
+    const { val, left, right } = root;
+    return `${val},${serialize(left)},${serialize(right)}`;
+};
+
+/**
+ * Decodes your encoded data to tree.
+ *
+ * @param {string} data
+ * @return {TreeNode}
+ */
+var deserialize = function (data) {
+    const vals = data.split(',');
+    let index = 0;
+    const dfs = () => {
+        if (vals[index] == '#') {
+            index++;
+            return null;
+        }
+        const res = new TreeNode(vals[index++]);
+        res.left = dfs();
+        res.right = dfs();
+        return res;
+    };
+    return dfs();
+};
+
+/**
+ * Your functions will be called as such:
+ * deserialize(serialize(root));
+ */
+```
+
 ### **...**
 
 ```

lcof/面试题38. 字符串的排列/README.md

@@ -156,6 +156,60 @@ public:
 };
 ```
 
+### **TypeScript**
+
+```ts
+function permutation(s: string): string[] {
+    const n = s.length;
+    const cs = s.split('');
+    const set = new Set<string>();
+    const dfs = (i: number) => {
+        if (i === n) {
+            set.add(cs.join(''));
+            return;
+        }
+        dfs(i + 1);
+        for (let j = i + 1; j < n; j++) {
+            [cs[i], cs[j]] = [cs[j], cs[i]];
+            dfs(i + 1);
+            [cs[i], cs[j]] = [cs[j], cs[i]];
+        }
+    };
+    dfs(0);
+    return [...set];
+}
+```
+
+### **Rust**
+
+```rust
+use std::collections::HashSet;
+impl Solution {
+    fn dfs(i: usize, cs: &mut Vec<char>, res: &mut Vec<String>) {
+        if i == cs.len() {
+            res.push(cs.iter().collect());
+            return;
+        }
+        let mut set = HashSet::new();
+        for j in i..cs.len() {
+            if set.contains(&cs[j]) {
+                continue;
+            }
+            set.insert(cs[j]);
+            cs.swap(i, j);
+            Self::dfs(i + 1, cs, res);
+            cs.swap(i, j);
+        }
+    }
+
+    pub fn permutation(s: String) -> Vec<String> {
+        let mut res = Vec::new();
+        Self::dfs(0, &mut s.chars().collect(), &mut res);
+        res
+    }
+}
+```
+
 ### **...**
 
 ```

lcof/面试题38. 字符串的排列/Solution.rs

@@ -0,0 +1,25 @@
+use std::collections::HashSet;
+impl Solution {
+    fn dfs(i: usize, cs: &mut Vec<char>, res: &mut Vec<String>) {
+        if i == cs.len() {
+            res.push(cs.iter().collect());
+            return;
+        }
+        let mut set = HashSet::new();
+        for j in i..cs.len() {
+            if set.contains(&cs[j]) {
+                continue;
+            }
+            set.insert(cs[j]);
+            cs.swap(i, j);
+            Self::dfs(i + 1, cs, res);
+            cs.swap(i, j);
+        }
+    }
+
+    pub fn permutation(s: String) -> Vec<String> {
+        let mut res = Vec::new();
+        Self::dfs(0, &mut s.chars().collect(), &mut res);
+        res
+    }
+}

lcof/面试题38. 字符串的排列/Solution.ts

@@ -0,0 +1,19 @@
+function permutation(s: string): string[] {
+    const n = s.length;
+    const cs = s.split('');
+    const set = new Set<string>();
+    const dfs = (i: number) => {
+        if (i === n) {
+            set.add(cs.join(''));
+            return;
+        }
+        dfs(i + 1);
+        for (let j = i + 1; j < n; j++) {
+            [cs[i], cs[j]] = [cs[j], cs[i]];
+            dfs(i + 1);
+            [cs[i], cs[j]] = [cs[j], cs[i]];
+        }
+    };
+    dfs(0);
+    return [...set];
+}

lcof/面试题59 - I. 滑动窗口的最大值/README.md

@@ -182,6 +182,72 @@ func maxSlidingWindow(nums []int, k int) []int {
 }
 ```
 
+### **TypeScript**
+
+```ts
+function maxSlidingWindow(nums: number[], k: number): number[] {
+    const n = nums.length;
+    const res = [];
+    if (n === 0 || k === 0) {
+        return res;
+    }
+    const queue = [];
+    for (let i = 0; i < k; i++) {
+        while (queue.length !== 0 && queue[queue.length - 1] < nums[i]) {
+            queue.pop();
+        }
+        queue.push(nums[i]);
+    }
+    res.push(queue[0]);
+    for (let i = k; i < n; i++) {
+        if (queue[0] === nums[i - k]) {
+            queue.shift();
+        }
+        while (queue.length !== 0 && queue[queue.length - 1] < nums[i]) {
+            queue.pop();
+        }
+        queue.push(nums[i]);
+        res.push(queue[0]);
+    }
+    return res;
+}
+```
+
+### **Rust**
+
+```rust
+use std::collections::VecDeque;
+impl Solution {
+    pub fn max_sliding_window(nums: Vec<i32>, k: i32) -> Vec<i32> {
+        let k = k as usize;
+        let n = nums.len();
+        if n == 0 || k == 0 {
+            return Vec::new();
+        }
+        let mut res = vec![0; n - k + 1];
+        let mut queue = VecDeque::new();
+        for i in 0..k {
+            while !queue.is_empty() && *queue.back().unwrap() < nums[i] {
+                queue.pop_back();
+            }
+            queue.push_back(nums[i]);
+        }
+        res[0] = queue[0];
+        for i in k..n {
+            if nums[i - k] == queue[0] {
+                queue.pop_front();
+            }
+            while !queue.is_empty() && *queue.back().unwrap() < nums[i] {
+                queue.pop_back();
+            }
+            queue.push_back(nums[i]);
+            res[i - k + 1] = queue[0];
+        }
+        res
+    }
+}
+```
+
 ### **...**
 
 ```

lcof/面试题59 - I. 滑动窗口的最大值/Solution.rs

@@ -0,0 +1,30 @@
+use std::collections::VecDeque;
+impl Solution {
+    pub fn max_sliding_window(nums: Vec<i32>, k: i32) -> Vec<i32> {
+        let k = k as usize;
+        let n = nums.len();
+        if n == 0 || k == 0 {
+            return Vec::new();
+        }
+        let mut res = vec![0; n - k + 1];
+        let mut queue = VecDeque::new();
+        for i in 0..k {
+            while !queue.is_empty() && *queue.back().unwrap() < nums[i] {
+                queue.pop_back();
+            }
+            queue.push_back(nums[i]);
+        }
+        res[0] = queue[0];
+        for i in k..n {
+            if nums[i - k] == queue[0] {
+                queue.pop_front();
+            }
+            while !queue.is_empty() && *queue.back().unwrap() < nums[i] {
+                queue.pop_back();
+            }
+            queue.push_back(nums[i]);
+            res[i - k + 1] = queue[0];
+        }
+        res
+    }
+}

lcof/面试题59 - I. 滑动窗口的最大值/Solution.ts

@@ -0,0 +1,26 @@
+function maxSlidingWindow(nums: number[], k: number): number[] {
+    const n = nums.length;
+    const res = [];
+    if (n === 0 || k === 0) {
+        return res;
+    }
+    const queue = [];
+    for (let i = 0; i < k; i++) {
+        while (queue.length !== 0 && queue[queue.length - 1] < nums[i]) {
+            queue.pop();
+        }
+        queue.push(nums[i]);
+    }
+    res.push(queue[0]);
+    for (let i = k; i < n; i++) {
+        if (queue[0] === nums[i - k]) {
+            queue.shift();
+        }
+        while (queue.length !== 0 && queue[queue.length - 1] < nums[i]) {
+            queue.pop();
+        }
+        queue.push(nums[i]);
+        res.push(queue[0]);
+    }
+    return res;
+}