Merge pull request #570 from notauserx/102-Binary-Tree-Level-Order-Traversal-csharp

Create 102-Binary-Tree-Level-Order-Traversal.cs

Author: Ahmad-A0

csharp/102-Binary-Tree-Level-Order-Traversal.cs

@@ -0,0 +1,42 @@
+/**
+ * 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;
+ *     }
+ * }
+ */
+public class Solution {  
+    public IList<IList<int>> LevelOrder(TreeNode root) {
+        var result = new List<IList<int>>();
+        if(root == null) return result;
+        
+        var q = new Queue<TreeNode>();
+        q.Enqueue(root);
+        
+        while(true) {
+            var curLevelCount = q.Count;
+            if(curLevelCount == 0) break;
+            var curNodes = new List<int>();
+            while(curLevelCount > 0) {
+                var cur = q.Dequeue();
+                curNodes.Add(cur.val);
+                
+                if(cur.left != null) 
+                    q.Enqueue(cur.left);
+                
+                if(cur.right != null) 
+                    q.Enqueue(cur.right);
+                curLevelCount--;
+            }
+            result.Add(curNodes);
+        }
+        
+        return result;
+    }
+}