Update 0112.路径总和.md

problems/0112.路径总和.md

@@ -1269,6 +1269,55 @@ impl Solution {
     }
 ```
 
+### 113.路径总和-ii
+
+```rust
+impl Solution {
+    pub fn path_sum(root: Option<Rc<RefCell<TreeNode>>>, target_sum: i32) -> Vec<Vec<i32>> {
+        let mut res = vec![];
+        let mut route = vec![];
+        if root.is_none() {
+            return res;
+        } else {
+            route.push(root.as_ref().unwrap().borrow().val);
+        }
+        Self::recur(
+            &root,
+            target_sum - root.as_ref().unwrap().borrow().val,
+            &mut res,
+            &mut route,
+        );
+        res
+    }
+
+    pub fn recur(
+        root: &Option<Rc<RefCell<TreeNode>>>,
+        sum: i32,
+        res: &mut Vec<Vec<i32>>,
+        route: &mut Vec<i32>,
+    ) {
+        let node = root.as_ref().unwrap().borrow();
+        if node.left.is_none() && node.right.is_none() && sum == 0 {
+            res.push(route.to_vec());
+            return;
+        }
+        if node.left.is_some() {
+            let left = node.left.as_ref().unwrap();
+            route.push(left.borrow().val);
+            Self::recur(&node.left, sum - left.borrow().val, res, route);
+            route.pop();
+        }
+        if node.right.is_some() {
+            let right = node.right.as_ref().unwrap();
+            route.push(right.borrow().val);
+            Self::recur(&node.right, sum - right.borrow().val, res, route);
+            route.pop();
+        }
+    }
+}
+
+```
+
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