Merge pull request #2415 from Chenxue3/master

Update 0513.找树左下角的值.md/0104.二叉树的最大深度.md/0112.路径总和.md

problems/0104.二叉树的最大深度.md

@@ -1033,6 +1033,9 @@ impl Solution {
     }
 ```
 ### C#
+
+0104.二叉树的最大深度
+
 ```csharp
 // 递归法
 public int MaxDepth(TreeNode root) {
@@ -1088,7 +1091,76 @@ public int MaxDepth(TreeNode root)
 }
 ```
 
+559.n叉树的最大深度 
+递归法
+```csharp
+     /*
+     递归法
+     */
+     public class Solution {
+       public int MaxDepth(Node root) {
+           int res = 0;
+           /* 终止条件 */
+           if(root == null){
+               return 0;
+           }
+
+           /* logic */
+           // 遍历当前节点的子节点
+           for (int i = 0; i < root.children.Count; i++)
+           {
+               res =  Math.Max(res, MaxDepth(root.children[i]));
+           }
+           return res + 1;
+       }
+     }
+     // @lc code=end
+```
+    迭代法（层序遍历）
+```csharp
+   /*
+   迭代法
+   */
+   public class Solution
+   {
+       public int MaxDepth(Node root)
+       {
+           Queue<Node> que = new Queue<Node>(); // 使用泛型队列存储节点
+
+           int res = 0;
+
+           if(root != null){
+               que.Enqueue(root); // 将根节点加入队列
+           }
+           while (que.Count > 0)
+           {
+               int size = que.Count; // 获取当前层的节点数
+               res++; // 深度加一
+
+               for (int i = 0; i < size; i++)
+               {
+                   // 每一层的遍历
+
+                   var curNode = que.Dequeue(); // 取出队列中的节点
+                   for (int j = 0; j < curNode.children.Count; j++)
+                   {
+                       if (curNode.children[j] != null)
+                       {
+                           que.Enqueue(curNode.children[j]); // 将子节点加入队列
+                       }
+                   }
+               }
+           }
+
+           return res; // 返回树的最大深度
+
+       }
+   }
+```
+
+
 <p align="center">
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">
   <img src="../pics/网站星球宣传海报.jpg" width="1000"/>
 </a>
+

problems/0112.路径总和.md

@@ -1523,8 +1523,64 @@ public bool HasPathSum(TreeNode root, int targetSum)
     return HasPathSum(root.left, targetSum - root.val) || HasPathSum(root.right, targetSum - root.val);
 }
 ```
+0113.路径总和：
+```csharp
+/*
+ * @lc app=leetcode id=113 lang=csharp
+ * 0113.路径总和 II
+ * [113] Path Sum II
+ * 递归法
+ */
+public class Solution {
+    private List<List<int>> result = new List<List<int>>();
+    private List<int> path = new List<int>();
 
+    // Main function to find paths with the given sum
+    public IList<IList<int>> PathSum(TreeNode root, int targetSum) {
+        result.Clear();
+        path.Clear();
+        if (root == null) return result.Select(list => list as IList<int>).ToList();
+        path.Add(root.val); // Add the root node to the path
+        traversal(root, targetSum - root.val); // Start the traversal
+        return result.Select(list => list as IList<int>).ToList();
+    }
+
+    // Recursive function to traverse the tree and find paths
+    private void traversal(TreeNode node, int count) {
+        // If a leaf node is reached and the target sum is achieved
+        if (node.left == null && node.right == null && count == 0) {
+            result.Add(new List<int>(path)); // Add a copy of the path to the result
+            return;
+        }
+
+        // If a leaf node is reached and the target sum is not achieved, or if it's not a leaf node
+        if (node.left == null && node.right == null) return;
+
+        // Traverse the left subtree
+        if (node.left != null) {
+            path.Add(node.left.val);
+            count -= node.left.val;
+            traversal(node.left, count);    // Recursive call
+            count += node.left.val;        // Backtrack
+            path.RemoveAt(path.Count - 1); // Backtrack
+        }
+
+        // Traverse the right subtree
+        if (node.right != null) {
+            path.Add(node.right.val);
+            count -= node.right.val;
+            traversal(node.right, count);   // Recursive call
+            count += node.right.val;       // Backtrack
+            path.RemoveAt(path.Count - 1); // Backtrack
+        }
+    }
+}
+
+// @lc code=end
+
+```
 <p align="center">
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">
   <img src="../pics/网站星球宣传海报.jpg" width="1000"/>
 </a>
+

problems/0513.找树左下角的值.md

@@ -716,9 +716,55 @@ public void Traversal(TreeNode root, int depth)
     return;
 }
 ```
+```csharp
+/*
+ * @lc app=leetcode id=513 lang=csharp
+ * 迭代法
+ * [513] Find Bottom Left Tree Value
+ */
+
+// @lc code=start
+public class Solution
+{
+    public int FindBottomLeftValue(TreeNode root)
+    {
+        Queue<TreeNode> que = new Queue<TreeNode>();
+
+        if (root != null)
+        {
+            que.Enqueue(root);
+        }
+        
+        int ans = 0;
+        while (que.Count != 0)
+        {
+           
+            int size = que.Count;
+            for (var i = 0; i < size; i++)
+            {
+                var curNode = que.Peek();
+                que.Dequeue();
+                if(i == 0){
+                    ans = curNode.val;
+                }
+                if (curNode.left != null)
+                {
+                    que.Enqueue(curNode.left);
+                }
+                if (curNode.right != null)
+                {
+                    que.Enqueue(curNode.right);
+                }
+            }
+
+        }
+        return ans;
+    }
+}
+// @lc code=end
+```
 
 <p align="center">
 <a href="https://programmercarl.com/other/kstar.html" target="_blank">
   <img src="../pics/网站星球宣传海报.jpg" width="1000"/>
 </a>
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