feat: add solutions to lc problem: No.0236

No.0236.Lowest Common Ancestor of a Binary Tree

Author: yanglbme

solution/0200-0299/0236.Lowest Common Ancestor of a Binary Tree/README.md

@@ -51,6 +51,8 @@
 
 <!-- 这里可写通用的实现逻辑 -->
 
+**方法一：递归**
+
 根据“**最近公共祖先**”的定义，若 root 是 p, q 的最近公共祖先 ，则只可能为以下情况之一：
 
 -   如果 p 和 q 分别是 root 的左右节点，那么 root 就是我们要找的最近公共祖先；
@@ -84,11 +86,7 @@ class Solution:
             return root
         left = self.lowestCommonAncestor(root.left, p, q)
         right = self.lowestCommonAncestor(root.right, p, q)
-        if left is None:
-            return right
-        if right is None:
-            return left
-        return root
+        return root if left and right else (left or right)
 ```
 
 ### **Java**
@@ -117,6 +115,57 @@ class Solution {
 }
 ```
 
+### **C++**
+
+```cpp
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+ * };
+ */
+class Solution {
+public:
+    TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
+        if (!root || root == p || root == q) return root;
+        TreeNode* left = lowestCommonAncestor(root->left, p, q);
+        TreeNode* right = lowestCommonAncestor(root->right, p, q);
+        if (left && right) return root;
+        return left ? left : right;
+    }
+};
+```
+
+### **Go**
+
+```go
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+func lowestCommonAncestor(root, p, q *TreeNode) *TreeNode {
+	if root == nil || root == p || root == q {
+		return root
+	}
+	left := lowestCommonAncestor(root.Left, p, q)
+	right := lowestCommonAncestor(root.Right, p, q)
+	if left == nil {
+		return right
+	}
+	if right == nil {
+		return left
+	}
+	return root
+}
+```
+
 ### **JavaScript**
 
 ```js

solution/0200-0299/0236.Lowest Common Ancestor of a Binary Tree/README_EN.md

@@ -63,11 +63,7 @@ class Solution:
             return root
         left = self.lowestCommonAncestor(root.left, p, q)
         right = self.lowestCommonAncestor(root.right, p, q)
-        if left is None:
-            return right
-        if right is None:
-            return left
-        return root
+        return root if left and right else (left or right)
 ```
 
 ### **Java**
@@ -94,6 +90,57 @@ class Solution {
 }
 ```
 
+### **C++**
+
+```cpp
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+ * };
+ */
+class Solution {
+public:
+    TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
+        if (!root || root == p || root == q) return root;
+        TreeNode* left = lowestCommonAncestor(root->left, p, q);
+        TreeNode* right = lowestCommonAncestor(root->right, p, q);
+        if (left && right) return root;
+        return left ? left : right;
+    }
+};
+```
+
+### **Go**
+
+```go
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+func lowestCommonAncestor(root, p, q *TreeNode) *TreeNode {
+	if root == nil || root == p || root == q {
+		return root
+	}
+	left := lowestCommonAncestor(root.Left, p, q)
+	right := lowestCommonAncestor(root.Right, p, q)
+	if left == nil {
+		return right
+	}
+	if right == nil {
+		return left
+	}
+	return root
+}
+```
+
 ### **JavaScript**
 
 ```js

solution/0200-0299/0236.Lowest Common Ancestor of a Binary Tree/Solution.cpp

@@ -0,0 +1,19 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+ * };
+ */
+class Solution {
+public:
+    TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {
+        if (!root || root == p || root == q) return root;
+        TreeNode* left = lowestCommonAncestor(root->left, p, q);
+        TreeNode* right = lowestCommonAncestor(root->right, p, q);
+        if (left && right) return root;
+        return left ? left : right;
+    }
+};

solution/0200-0299/0236.Lowest Common Ancestor of a Binary Tree/Solution.go

@@ -0,0 +1,22 @@
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+func lowestCommonAncestor(root, p, q *TreeNode) *TreeNode {
+	if root == nil || root == p || root == q {
+		return root
+	}
+	left := lowestCommonAncestor(root.Left, p, q)
+	right := lowestCommonAncestor(root.Right, p, q)
+	if left == nil {
+		return right
+	}
+	if right == nil {
+		return left
+	}
+	return root
+}

solution/0200-0299/0236.Lowest Common Ancestor of a Binary Tree/Solution.py

@@ -14,8 +14,4 @@ def lowestCommonAncestor(
             return root
         left = self.lowestCommonAncestor(root.left, p, q)
         right = self.lowestCommonAncestor(root.right, p, q)
-        if left is None:
-            return right
-        if right is None:
-            return left
-        return root
+        return root if left and right else (left or right)

solution/2200-2299/2290.Minimum Obstacle Removal to Reach Corner/Solution.py

@@ -17,4 +17,4 @@ def minimumObstacles(self, grid: List[List[int]]) -> int:
                         q.appendleft((x, y, k))
                     else:
                         q.append((x, y, k + 1))
-        return 0
+        return 0

solution/contest.py

@@ -60,7 +60,7 @@ def handle(result: dict):
             'contest_title_slug': result['contest']['title_slug'],
             'contest_id': result['contest']['id'],
             'contest_start_time': result['contest']['origin_start_time'],
-            'contest_duration': result['contest']['duration']
+            'contest_duration': result['contest']['duration'],
         }
 
 
@@ -80,10 +80,16 @@ def run():
         biweekly_res.append(res)
     for v in chain(weekly_res, biweekly_res):
         handle(v)
-        contest_list.append([
-            v['contest']['id'], v['title'], v['title_en'], v['questions'], v['contest']['start_time'],
-            v['contest']['duration']
-        ])
+        contest_list.append(
+            [
+                v['contest']['id'],
+                v['title'],
+                v['title_en'],
+                v['questions'],
+                v['contest']['start_time'],
+                v['contest']['duration'],
+            ]
+        )
 
     contest_list.sort(reverse=True)
     with open("contest.json", 'w', encoding='utf-8') as f:
@@ -94,6 +100,7 @@ def run():
 
 # ["id", "title", "title_en", "questions", "start_time", "duration"]
 
+
 def generate_contest_list():
     with open('./result.json', 'r', encoding='utf-8') as f:
         result = json.loads(f.read())
@@ -112,7 +119,12 @@ def generate_contest_list():
     en_items = []
 
     for cid, title, title_en, qs, start_time, duration in contest_list:
-        v = "#### " + title + f'({format_time(start_time) + ", " + format_duration(duration)})' + "\n\n"
+        v = (
+            "#### "
+            + title
+            + f'({format_time(start_time) + ", " + format_duration(duration)})'
+            + "\n\n"
+        )
         v_en = "#### " + title_en + "\n\n"
         for q in qs:
             slug = q['title_slug']

solution/main.py

@@ -152,10 +152,10 @@ def refresh(result):
             en_content = f2.read()
         i = cn_content.index('. ')
         j = cn_content.index(']')
-        cn_content = cn_content.replace(cn_content[i + 2: j], title)
+        cn_content = cn_content.replace(cn_content[i + 2 : j], title)
         i = en_content.index('. ')
         j = en_content.index(']')
-        en_content = en_content.replace(en_content[i + 2: j], title_en)
+        en_content = en_content.replace(en_content[i + 2 : j], title_en)
 
         # update question content
         old_content = re.search("<!-- 这里写题目描述 -->(.*?)## 解法", cn_content, re.S).group(1)