Merge branch 'youngyangyang04:master' into leetcode-modify-the-code-of-the-BinaryTree

problems/0027.移除元素.md

@@ -77,7 +77,7 @@ public:
 
 双指针法（快慢指针法）： **通过一个快指针和慢指针在一个for循环下完成两个for循环的工作。**
 
-定义快慢指针 
+定义快慢指针
 
 * 快指针：寻找新数组的元素 ，新数组就是不含有目标元素的数组
 * 慢指针：指向更新 新数组下标的位置
@@ -196,21 +196,26 @@ class Solution {
 
 Python：
 
-```python3
+
+``` python 3
 class Solution:
     def removeElement(self, nums: List[int], val: int) -> int:
-        # 快指针遍历元素
-        fast = 0
-        # 慢指针记录位置
-        slow = 0
-        for fast in range(len(nums)):
+        # 快慢指针
+        fast = 0  # 快指针
+        slow = 0  # 慢指针
+        size = len(nums)
+        while fast < size:  # 不加等于是因为，a = size 时，nums[a] 会越界
+            # slow 用来收集不等于 val 的值，如果 fast 对应值不等于 val，则把它与 slow 替换
             if nums[fast] != val:
                 nums[slow] = nums[fast]
                 slow += 1
+            fast += 1
         return slow
 ```
 
 
+
+
 Go：
 ```go
 func removeElement(nums []int, val int) int {
@@ -262,7 +267,7 @@ Ruby:
 ```ruby
 def remove_element(nums, val)
     i = 0
-    nums.each_index do |j| 
+    nums.each_index do |j|
         if nums[j] != val
             nums[i] = nums[j]
             i+=1
@@ -336,7 +341,7 @@ int removeElement(int* nums, int numsSize, int val){
         if(nums[fast] != val) {
             //将其挪到慢指针指向的位置，慢指针+1
             nums[slow++] = nums[fast];
-        } 
+        }
     }
     //最后慢指针的大小就是新的数组的大小
     return slow;

problems/0110.平衡二叉树.md

@@ -805,6 +805,38 @@ func getHeight(_ root: TreeNode?) -> Int {
 }
 ```
 
+### rust
+
+递归
+
+```rust
+use std::cell::RefCell;
+use std::rc::Rc;
+impl Solution {
+    pub fn is_balanced(root: Option<Rc<RefCell<TreeNode>>>) -> bool {
+        Self::get_depth(root) != -1
+    }
+    pub fn get_depth(root: Option<Rc<RefCell<TreeNode>>>) -> i32 {
+        if root.is_none() {
+            return 0;
+        }
+        let right = Self::get_depth(root.as_ref().unwrap().borrow().left.clone());
+        let left = Self::get_depth(root.unwrap().borrow().right.clone());
+        if right == -1 {
+            return -1;
+        }
+        if left == -1 {
+            return -1;
+        }
+        if (right - left).abs() > 1 {
+            return -1;
+        }
+
+        1 + right.max(left)
+    }
+}
+```
+
 <p align="center">
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">
   <img src="../pics/网站星球宣传海报.jpg" width="1000"/>

problems/0222.完全二叉树的节点个数.md

@@ -793,6 +793,52 @@ object Solution {
 }
 ```
 
+rust:
+
+// 递归
+```rust
+use std::cell::RefCell;
+use std::rc::Rc;
+impl Solution {
+    pub fn count_nodes(root: Option<Rc<RefCell<TreeNode>>>) -> i32 {
+        if root.is_none() {
+            return 0;
+        }
+        1 + Self::count_nodes(Rc::clone(root.as_ref().unwrap()).borrow().left.clone())
+            + Self::count_nodes(root.unwrap().borrow().right.clone())
+    }
+}
+```
+
+// 迭代
+```rust
+use std::rc::Rc;
+use std::cell::RefCell;
+use std::collections::VecDeque;
+impl Solution {
+    pub fn count_nodes(root: Option<Rc<RefCell<TreeNode>>>) -> i32 {
+        let mut res = 0;
+        let mut queue = VecDeque::new();
+        if root.is_some() {
+            queue.push_back(root);
+        }
+        while !queue.is_empty() {
+            for _ in 0..queue.len() {
+                let node = queue.pop_front().unwrap().unwrap();
+                if node.borrow().left.is_some() {
+                    queue.push_back(node.borrow().left.clone());
+                }
+                if node.borrow().right.is_some() {
+                    queue.push_back(node.borrow().right.clone());
+                }
+                res += 1;
+            }
+        }
+        res
+    }
+}
+```
+
 <p align="center">
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">
   <img src="../pics/网站星球宣传海报.jpg" width="1000"/>

problems/0257.二叉树的所有路径.md

@@ -794,6 +794,33 @@ object Solution {
   }
 }
 ```
+	
+rust:
+
+```rust
+// 递归
+impl Solution {
+    pub fn binary_tree_paths(root: Option<Rc<RefCell<TreeNode>>>) -> Vec<String> {
+        let mut res = vec![];
+        Self::recur(&root, String::from(""), &mut res);
+        res
+    }
+    pub fn recur(node: &Option<Rc<RefCell<TreeNode>>>, mut path: String, res: &mut Vec<String>) {
+        let r = node.as_ref().unwrap().borrow();
+        path += format!("{}", r.val).as_str();
+        if r.left.is_none() && r.right.is_none() {
+            res.push(path.to_string());
+            return;
+        }
+        if r.left.is_some() {
+            Self::recur(&r.left, path.clone() + "->", res);
+        }
+        if r.right.is_some() {
+            Self::recur(&r.right, path + "->", res);
+        }
+    }
+}
+```
 
 <p align="center">
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">