Day6. Namespace style

102. Binary Tree Level Order Traversal/102. Binary Tree Level Order Traversal.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <RootNamespace>_102._Binary_Tree_Level_Order_Traversal</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

102. Binary Tree Level Order Traversal/Program.cs

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+namespace _102._Binary_Tree_Level_Order_Traversal;
+
+internal class Program
+{
+    static void Main(string[] args)
+    {
+        Console.WriteLine("Hello, World!");
+    }
+}

102. Binary Tree Level Order Traversal/Solution.cs

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+namespace _102._Binary_Tree_Level_Order_Traversal;
+
+public class Solution
+{
+    public IList<IList<int>> LevelOrder(TreeNode root)
+    {
+        List<IList<int>> output = new List<IList<int>>();
+        RecursiveTraversal(output, new List<TreeNode>() { root });
+        return output;
+    }
+
+    private void RecursiveTraversal(List<IList<int>> output, List<TreeNode> curLevel)
+    {
+        if (curLevel.Count == 0)
+            return;
+        List<int> levelValues = new List<int>();
+        foreach (var n in curLevel)
+        {
+            if (n == null)
+                continue;
+            levelValues.Add(n.val);
+        }
+        if (levelValues.Count == 0)
+            return;
+        output.Add(levelValues);
+
+        List<TreeNode> nextLevel = new List<TreeNode>();
+        foreach (var n in curLevel)
+        {
+            if (n == null)
+                continue;
+            if (n.left != null)
+                nextLevel.Add(n.left);
+            if (n.right != null)
+                nextLevel.Add(n.right);
+        }
+        RecursiveTraversal(output, nextLevel);
+    }
+}

102. Binary Tree Level Order Traversal/TreeNode.cs

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+namespace _102._Binary_Tree_Level_Order_Traversal;
+
+
+//Definition for a binary tree node.
+public class TreeNode
+{
+    public int val;
+    public TreeNode? left;
+    public TreeNode? right;
+    public TreeNode(int val = 0, TreeNode? left = null, TreeNode? right = null)
+    {
+        this.val = val;
+        this.left = left;
+        this.right = right;
+    }
+}
+