feat: update solutions to lc problem: No.1490

No.1490.Clone N-ary Tree

Author: yanglbme

solution/1400-1499/1486.XOR Operation in an Array/README.md

@@ -75,6 +75,12 @@ class Solution:
         return ans
 ```
 
+```python
+class Solution:
+    def xorOperation(self, n: int, start: int) -> int:
+        return reduce(xor, ((start + 2 * i) for i in range(n)))
+```
+
 ### **Java**
 
 <!-- 这里可写当前语言的特殊实现逻辑 -->

solution/1400-1499/1486.XOR Operation in an Array/README_EN.md

@@ -52,6 +52,12 @@ class Solution:
         return ans
 ```
 
+```python
+class Solution:
+    def xorOperation(self, n: int, start: int) -> int:
+        return reduce(xor, ((start + 2 * i) for i in range(n)))
+```
+
 ### **Java**
 
 ```java

solution/1400-1499/1490.Clone N-ary Tree/README.md

@@ -56,7 +56,13 @@ class Node {
 
 <!-- 这里可写通用的实现逻辑 -->
 
-DFS。
+**方法一：递归**
+
+我们可以用递归的方法来实现 N 叉树的深拷贝。
+
+对于当前节点，如果为空，则返回空；否则，创建一个新节点，其值为当前节点的值，然后对当前节点的每个子节点递归调用该函数，将返回值作为新节点的子节点。最后返回新节点即可。
+
+时间复杂度 $O(n)$，空间复杂度 $O(n)$。其中 $n$ 为 N 叉树的节点个数。
 
 <!-- tabs:start -->
 
@@ -76,10 +82,10 @@ class Node:
 
 class Solution:
     def cloneTree(self, root: 'Node') -> 'Node':
-        if root:
-            node = Node(val=root.val)
-            node.children = [self.cloneTree(child) for child in root.children]
-            return node
+        if root is None:
+            return None
+        children = [self.cloneTree(child) for child in root.children]
+        return Node(root.val, children)
 ```
 
 ### **Java**
@@ -115,11 +121,11 @@ class Solution {
         if (root == null) {
             return null;
         }
-        Node node = new Node(root.val);
+        ArrayList<Node> children = new ArrayList<>();
         for (Node child : root.children) {
-            node.children.add(cloneTree(child));
+            children.add(cloneTree(child));
         }
-        return node;
+        return new Node(root.val, children);
     }
 }
 ```
@@ -150,16 +156,14 @@ public:
 class Solution {
 public:
     Node* cloneTree(Node* root) {
-        if (root == nullptr) {
-            return nullptr;
+        if (!root) {
+            return root;
         }
-        Node* node = new Node(root->val);
         vector<Node*> children;
-        for (Node* node : root->children) {
-            children.push_back(cloneTree(node));
+        for (Node* child : root->children) {
+            children.emplace_back(cloneTree(child));
         }
-        node->children = children;
-        return node;
+        return new Node(root->val, children);
     }
 };
 ```
@@ -179,11 +183,11 @@ func cloneTree(root *Node) *Node {
 	if root == nil {
 		return nil
 	}
-	node := &Node{Val: root.Val}
+	children := []*Node{}
 	for _, child := range root.Children {
-		node.Children = append(node.Children, cloneTree(child))
+		children = append(children, cloneTree(child))
 	}
-	return node
+	return &Node{root.Val, children}
 }
 ```
 

solution/1400-1499/1490.Clone N-ary Tree/README_EN.md

@@ -67,10 +67,10 @@ class Node:
 
 class Solution:
     def cloneTree(self, root: 'Node') -> 'Node':
-        if root:
-            node = Node(val=root.val)
-            node.children = [self.cloneTree(child) for child in root.children]
-            return node
+        if root is None:
+            return None
+        children = [self.cloneTree(child) for child in root.children]
+        return Node(root.val, children)
 ```
 
 ### **Java**
@@ -104,11 +104,11 @@ class Solution {
         if (root == null) {
             return null;
         }
-        Node node = new Node(root.val);
+        ArrayList<Node> children = new ArrayList<>();
         for (Node child : root.children) {
-            node.children.add(cloneTree(child));
+            children.add(cloneTree(child));
         }
-        return node;
+        return new Node(root.val, children);
     }
 }
 ```
@@ -139,16 +139,14 @@ public:
 class Solution {
 public:
     Node* cloneTree(Node* root) {
-        if (root == nullptr) {
-            return nullptr;
+        if (!root) {
+            return root;
         }
-        Node* node = new Node(root->val);
         vector<Node*> children;
-        for (Node* node : root->children) {
-            children.push_back(cloneTree(node));
+        for (Node* child : root->children) {
+            children.emplace_back(cloneTree(child));
         }
-        node->children = children;
-        return node;
+        return new Node(root->val, children);
     }
 };
 ```
@@ -168,11 +166,11 @@ func cloneTree(root *Node) *Node {
 	if root == nil {
 		return nil
 	}
-	node := &Node{Val: root.Val}
+	children := []*Node{}
 	for _, child := range root.Children {
-		node.Children = append(node.Children, cloneTree(child))
+		children = append(children, cloneTree(child))
 	}
-	return node
+	return &Node{root.Val, children}
 }
 ```
 

solution/1400-1499/1490.Clone N-ary Tree/Solution.cpp

@@ -21,15 +21,13 @@ class Node {
 class Solution {
 public:
     Node* cloneTree(Node* root) {
-        if (root == nullptr) {
-            return nullptr;
+        if (!root) {
+            return root;
         }
-        Node* node = new Node(root->val);
         vector<Node*> children;
-        for (Node* node : root->children) {
-            children.push_back(cloneTree(node));
+        for (Node* child : root->children) {
+            children.emplace_back(cloneTree(child));
         }
-        node->children = children;
-        return node;
+        return new Node(root->val, children);
     }
 };

solution/1400-1499/1490.Clone N-ary Tree/Solution.go

@@ -10,9 +10,9 @@ func cloneTree(root *Node) *Node {
 	if root == nil {
 		return nil
 	}
-	node := &Node{Val: root.Val}
+	children := []*Node{}
 	for _, child := range root.Children {
-		node.Children = append(node.Children, cloneTree(child))
+		children = append(children, cloneTree(child))
 	}
-	return node
+	return &Node{root.Val, children}
 }

solution/1400-1499/1490.Clone N-ary Tree/Solution.java

@@ -4,16 +4,16 @@ class Node {
     public int val;
     public List<Node> children;
 
-
+    
     public Node() {
         children = new ArrayList<Node>();
     }
-
+    
     public Node(int _val) {
         val = _val;
         children = new ArrayList<Node>();
     }
-
+    
     public Node(int _val,ArrayList<Node> _children) {
         val = _val;
         children = _children;
@@ -26,10 +26,10 @@ public Node cloneTree(Node root) {
         if (root == null) {
             return null;
         }
-        Node node = new Node(root.val);
+        ArrayList<Node> children = new ArrayList<>();
         for (Node child : root.children) {
-            node.children.add(cloneTree(child));
+            children.add(cloneTree(child));
         }
-        return node;
+        return new Node(root.val, children);
     }
 }

solution/1400-1499/1490.Clone N-ary Tree/Solution.py

@@ -9,7 +9,7 @@ def __init__(self, val=None, children=None):
 
 class Solution:
     def cloneTree(self, root: 'Node') -> 'Node':
-        if root:
-            node = Node(val=root.val)
-            node.children = [self.cloneTree(child) for child in root.children]
-            return node
+        if root is None:
+            return None
+        children = [self.cloneTree(child) for child in root.children]
+        return Node(root.val, children)

solution/1500-1599/1510.Stone Game IV/README_EN.md

@@ -85,12 +85,12 @@ class Solution:
 ```java
 class Solution {
     private Boolean[] f;
-    
+
     public boolean winnerSquareGame(int n) {
         f = new Boolean[n + 1];
         return dfs(n);
     }
-    
+
     private boolean dfs(int i) {
         if (i <= 0) {
             return false;

solution/1800-1899/1845.Seat Reservation Manager/README_EN.md

@@ -84,11 +84,11 @@ class SeatManager {
             q.offer(i);
         }
     }
-    
+
     public int reserve() {
         return q.poll();
     }
-    
+
     public void unreserve(int seatNumber) {
         q.offer(seatNumber);
     }
@@ -112,13 +112,13 @@ public:
             q.push(i);
         }
     }
-    
+
     int reserve() {
         int seat = q.top();
         q.pop();
         return seat;
     }
-    
+
     void unreserve(int seatNumber) {
         q.push(seatNumber);
     }