Merge pull request #1753 from Jack-Zhang-1314/patch-12

Update 0101.对称二叉树.md about rust

problems/0101.对称二叉树.md

@@ -826,6 +826,67 @@ object Solution {
 }
 ```
 
+## Rust
+
+递归：
+```rust
+impl Solution {
+    pub fn is_symmetric(root: Option<Rc<RefCell<TreeNode>>>) -> bool {
+        Self::recur(
+            &root.as_ref().unwrap().borrow().left,
+            &root.as_ref().unwrap().borrow().right,
+        )
+    }
+    pub fn recur(
+        left: &Option<Rc<RefCell<TreeNode>>>,
+        right: &Option<Rc<RefCell<TreeNode>>>,
+    ) -> bool {
+        match (left, right) {
+            (None, None) => true,
+            (Some(n1), Some(n2)) => {
+                return n1.borrow().val == n2.borrow().val
+                    && Self::recur(&n1.borrow().left, &n2.borrow().right)
+                    && Self::recur(&n1.borrow().right, &n2.borrow().left)
+            }
+            _ => false,
+        }
+    }
+}
+```
+
+迭代：
+```rust
+use std::cell::RefCell;
+use std::collections::VecDeque;
+use std::rc::Rc;
+impl Solution {
+    pub fn is_symmetric(root: Option<Rc<RefCell<TreeNode>>>) -> bool {
+        let mut queue = VecDeque::new();
+        if let Some(node) = root {
+            queue.push_back(node.borrow().left.clone());
+            queue.push_back(node.borrow().right.clone());
+        }
+        while !queue.is_empty() {
+            let (n1, n2) = (queue.pop_front().unwrap(), queue.pop_front().unwrap());
+            match (n1.clone(), n2.clone()) {
+                (None, None) => continue,
+                (Some(n1), Some(n2)) => {
+                    if n1.borrow().val != n2.borrow().val {
+                        return false;
+                    }
+                }
+                _ => return false,
+            };
+            queue.push_back(n1.as_ref().unwrap().borrow().left.clone());
+            queue.push_back(n2.as_ref().unwrap().borrow().right.clone());
+            queue.push_back(n1.unwrap().borrow().right.clone());
+            queue.push_back(n2.unwrap().borrow().left.clone());
+        }
+        true
+    }
+}
+```
+
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