Update 0337.打家劫舍III.md about rust

problems/0337.打家劫舍III.md

@@ -490,6 +490,33 @@ function robNode(node: TreeNode | null): MaxValueArr {
 }
 ```
 
+### Rust
+
+动态规划：
+
+```rust
+use std::cell::RefCell;
+use std::rc::Rc;
+impl Solution {
+    pub fn rob(root: Option<Rc<RefCell<TreeNode>>>) -> i32 {
+        let (v1, v2) = Self::rob_tree(&root);
+        v1.max(v2)
+    }
+    pub fn rob_tree(cur: &Option<Rc<RefCell<TreeNode>>>) -> (i32, i32) {
+        match cur {
+            None => (0, 0),
+            Some(node) => {
+                let left = Self::rob_tree(&node.borrow_mut().left);
+                let right = Self::rob_tree(&node.borrow_mut().right);
+                (
+                    left.0.max(left.1) + right.0.max(right.1), // 偷左右节点
+                    node.borrow().val + left.0 + right.0,      // 偷父节点
+                )
+            }
+        }
+    }
+}
+```
 
 
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