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Author: assassint2017

Average of Levels in Binary Tree/Average_of_Levels_in_Binary_Tree.cpp

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+// Runtime: 20 ms, faster than 69.74% of C++ online submissions for Average of Levels in Binary Tree.
+// Memory Usage: 21.7 MB, less than 77.78% of C++ online submissions for Average of Levels in Binary Tree.
+
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+ * };
+ */
+class Solution 
+{
+public:
+    vector<double> averageOfLevels(TreeNode* root) 
+    {
+        vector<double> res;
+        if (root == nullptr)
+            return res;
+        
+        queue<TreeNode*> memo;
+        memo.push(root);
+        
+        while (!memo.empty())
+        {
+            double size = memo.size();
+            double temp = 0;
+            
+            for (int i = memo.size(); i > 0; --i)
+            {
+                root = memo.front();
+                memo.pop();
+                
+                temp += root->val;
+                
+                if (root->left) memo.push(root->left);
+                if (root->right) memo.push(root->right);
+            }
+            
+            res.push_back(temp / size);
+        }
+        return res;
+    }
+};