Update 102.二叉树的层序遍历，添加C#版

problems/0102.二叉树的层序遍历.md

@@ -462,6 +462,32 @@ impl Solution {
     }
 }
 ```
+### C#
+```C#
+public IList<IList<int>> LevelOrder(TreeNode root)
+{
+    var res = new List<IList<int>>();
+    var que = new Queue<TreeNode>();
+    if (root == null) return res;
+    que.Enqueue(root);
+    while (que.Count != 0)
+    {
+        var size = que.Count;
+        var vec = new List<int>();
+        for (int i = 0; i < size; i++)
+        {
+            var cur = que.Dequeue();
+            vec.Add(cur.val);
+            if (cur.left != null) que.Enqueue(cur.left);
+            if (cur.right != null) que.Enqueue(cur.right);
+        }
+        res.Add(vec);
+
+
+    }
+    return res;
+}
+```
 
 
 **此时我们就掌握了二叉树的层序遍历了，那么如下九道力扣上的题目，只需要修改模板的两三行代码（不能再多了），便可打倒！**
@@ -798,6 +824,31 @@ impl Solution {
     }
 }
 ```
+### C#
+```C#
+public IList<IList<int>> LevelOrderBottom(TreeNode root)
+{
+    var res = new List<IList<int>>();
+    var que = new Queue<TreeNode>();
+    if (root == null) return res;
+    que.Enqueue(root);
+    while (que.Count != 0)
+    {
+        var size = que.Count;
+        var vec = new List<int>();
+        for (int i = 0; i < size; i++)
+        {
+            var cur = que.Dequeue();
+            vec.Add(cur.val);
+            if (cur.left != null) que.Enqueue(cur.left);
+            if (cur.right != null) que.Enqueue(cur.right);
+        }
+        res.Add(vec);
+    }
+    res.Reverse();
+    return res;
+}
+```
 
 ## 199.二叉树的右视图