Merge pull request #1675 from Jack-Zhang-1314/patch-6

update 0024.两两交换链表中的节点 about rust

problems/0024.两两交换链表中的节点.md

@@ -380,5 +380,51 @@ function swapPairs($head)
 }
 ```
 
+Rust:
+
+```rust
+// 虚拟头节点
+impl Solution {
+    pub fn swap_pairs(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
+        let mut dummy_head = Box::new(ListNode::new(0));
+        dummy_head.next = head;
+        let mut cur = dummy_head.as_mut();
+        while let Some(mut node) = cur.next.take() {
+            if let Some(mut next) = node.next.take() {
+                node.next = next.next.take();
+                next.next = Some(node);
+                cur.next = Some(next);
+                cur = cur.next.as_mut().unwrap().next.as_mut().unwrap();
+            } else {
+                cur.next = Some(node);
+                cur = cur.next.as_mut().unwrap();
+            }
+        }
+        dummy_head.next
+    }
+}
+```
+
+```rust
+// 递归
+impl Solution {
+    pub fn swap_pairs(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
+        if head == None || head.as_ref().unwrap().next == None {
+            return head;
+        }
+
+        let mut node = head.unwrap();
+
+        if let Some(mut next) = node.next.take() {
+            node.next = Solution::swap_pairs(next.next);
+            next.next = Some(node);
+            Some(next)
+        } else {
+            Some(node)
+        }
+    }
+}
+```
+
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