feat: add solutions to lcof problem: No.68 - ||

面试题68 - II. 二叉树的最近公共祖先

Author: YangFong

lcof/面试题68 - II. 二叉树的最近公共祖先/README.md

@@ -192,6 +192,97 @@ func lowestCommonAncestor(root, p, q *TreeNode) *TreeNode {
 }
 ```
 
+### **TypeScript**
+
+```ts
+/**
+ * Definition for a binary tree node.
+ * class TreeNode {
+ *     val: number
+ *     left: TreeNode | null
+ *     right: TreeNode | null
+ *     constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.left = (left===undefined ? null : left)
+ *         this.right = (right===undefined ? null : right)
+ *     }
+ * }
+ */
+function lowestCommonAncestor(
+    root: TreeNode | null,
+    p: TreeNode | null,
+    q: TreeNode | null,
+): TreeNode | null {
+    if (root == null || root === p || root === q) {
+        return root;
+    }
+    const left = lowestCommonAncestor(root.left, p, q);
+    const right = lowestCommonAncestor(root.right, p, q);
+    if (left == null && right == null) {
+        return null;
+    }
+    if (left == null) {
+        return right;
+    }
+    if (right == null) {
+        return left;
+    }
+    return root;
+}
+```
+
+### **Rust**
+
+```rust
+// Definition for a binary tree node.
+// #[derive(Debug, PartialEq, Eq)]
+// pub struct TreeNode {
+//   pub val: i32,
+//   pub left: Option<Rc<RefCell<TreeNode>>>,
+//   pub right: Option<Rc<RefCell<TreeNode>>>,
+// }
+//
+// impl TreeNode {
+//   #[inline]
+//   pub fn new(val: i32) -> Self {
+//     TreeNode {
+//       val,
+//       left: None,
+//       right: None
+//     }
+//   }
+// }
+use std::rc::Rc;
+use std::cell::RefCell;
+impl Solution {
+    pub fn lowest_common_ancestor(
+        root: Option<Rc<RefCell<TreeNode>>>,
+        p: Option<Rc<RefCell<TreeNode>>>,
+        q: Option<Rc<RefCell<TreeNode>>>,
+    ) -> Option<Rc<RefCell<TreeNode>>> {
+        if root.is_none() || root == p || root == q {
+            return root;
+        }
+        let left = Self::lowest_common_ancestor(
+            root.as_ref().unwrap().borrow_mut().left.take(),
+            p.clone(),
+            q.clone(),
+        );
+        let right = Self::lowest_common_ancestor(
+            root.as_ref().unwrap().borrow_mut().right.take(),
+            p.clone(),
+            q.clone(),
+        );
+        match (left.is_none(), right.is_none()) {
+            (true, false) => right,
+            (false, true) => left,
+            (false, false) => root,
+            (true, true) => None,
+        }
+    }
+}
+```
+
 ### **...**
 
 ```

lcof/面试题68 - II. 二叉树的最近公共祖先/Solution.rs

@@ -0,0 +1,47 @@
+// Definition for a binary tree node.
+// #[derive(Debug, PartialEq, Eq)]
+// pub struct TreeNode {
+//   pub val: i32,
+//   pub left: Option<Rc<RefCell<TreeNode>>>,
+//   pub right: Option<Rc<RefCell<TreeNode>>>,
+// }
+//
+// impl TreeNode {
+//   #[inline]
+//   pub fn new(val: i32) -> Self {
+//     TreeNode {
+//       val,
+//       left: None,
+//       right: None
+//     }
+//   }
+// }
+use std::rc::Rc;
+use std::cell::RefCell;
+impl Solution {
+    pub fn lowest_common_ancestor(
+        root: Option<Rc<RefCell<TreeNode>>>,
+        p: Option<Rc<RefCell<TreeNode>>>,
+        q: Option<Rc<RefCell<TreeNode>>>,
+    ) -> Option<Rc<RefCell<TreeNode>>> {
+        if root.is_none() || root == p || root == q {
+            return root;
+        }
+        let left = Self::lowest_common_ancestor(
+            root.as_ref().unwrap().borrow_mut().left.take(),
+            p.clone(),
+            q.clone(),
+        );
+        let right = Self::lowest_common_ancestor(
+            root.as_ref().unwrap().borrow_mut().right.take(),
+            p.clone(),
+            q.clone(),
+        );
+        match (left.is_none(), right.is_none()) {
+            (true, false) => right,
+            (false, true) => left,
+            (false, false) => root,
+            (true, true) => None,
+        }
+    }
+}

lcof/面试题68 - II. 二叉树的最近公共祖先/Solution.ts

@@ -0,0 +1,34 @@
+/**
+ * Definition for a binary tree node.
+ * class TreeNode {
+ *     val: number
+ *     left: TreeNode | null
+ *     right: TreeNode | null
+ *     constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
+ *         this.val = (val===undefined ? 0 : val)
+ *         this.left = (left===undefined ? null : left)
+ *         this.right = (right===undefined ? null : right)
+ *     }
+ * }
+ */
+function lowestCommonAncestor(
+    root: TreeNode | null,
+    p: TreeNode | null,
+    q: TreeNode | null,
+): TreeNode | null {
+    if (root == null || root === p || root === q) {
+        return root;
+    }
+    const left = lowestCommonAncestor(root.left, p, q);
+    const right = lowestCommonAncestor(root.right, p, q);
+    if (left == null && right == null) {
+        return null;
+    }
+    if (left == null) {
+        return right;
+    }
+    if (right == null) {
+        return left;
+    }
+    return root;
+}