Commit 08a7ad6

author

Yu Zhou

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quick update 235

1 parent 7998521 commit 08a7ad6Copy full SHA for 08a7ad6

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+34

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Lines changed: 1 addition & 1 deletion

Original file line number	Diff line number	Diff line change
`@@ -109,7 +109,7 @@`
`109`	`109`	`\|270\|[Closest Binary Search Tree Value](https://leetcode.com/problems/closest-binary-search-tree-value/#/description)\| [Python ](./tree/Yu/270.py)\| _O(N)_\| _O(1)_\|[:tv:](https://youtu.be/RwvQyKJxHZk)\|`
`110`	`110`	`\|563\|[Binary Tree Tilt](https://leetcode.com/problems/binary-tree-tilt/#/description)\| [Python ](./tree/Yu/563.py) \| _O(N)_\| _O(1)_ \|[:tv:](https://youtu.be/47FQVP4ynk0)\|`
`111`	`111`	`\|538\|[Convert BST to Greater Tree](https://leetcode.com/problems/convert-bst-to-greater-tree/#/description)\| [Python ](./tree/Yu/538.py) \| _O(N)_\| _O(1)_ \|[:tv:](https://youtu.be/YoEPWtXmkD4)\|`
`112`		`-`
	`112`	`+\|637\|[Average of Levels in Binary Tree](https://leetcode.com/problems/average-of-levels-in-binary-tree/)\|[Python ](./tree/Yu/637.py)\|_O(N)_\|_O(1)_\|\|`
`113`	`113`
`114`	`114`	`## Tree Medium`
`115`	`115`	`\| # \| Title \| Solution \| Time \| Space \| Video\|`

Lines changed: 33 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,33 @@`
	`1`	`+class Solution(object):`
	`2`	`+ # DFS Recursion`
	`3`	`+ def averageOfLevels(self, root):`
	`4`	`+ self.res = []`
	`5`	`+`
	`6`	`+ def dfs(root, level):`
	`7`	`+ if not root:`
	`8`	`+ return []`
	`9`	`+ if len(self.res) == level:`
	`10`	`+ self.res.append([])`
	`11`	`+ self.res[level].append(root.val)`
	`12`	`+ dfs(root.left, level + 1)`
	`13`	`+ dfs(root.right, level + 1)`
	`14`	`+`
	`15`	`+ dfs(root, 0)`
	`16`	`+ return [sum(num)/float(len(num)) for num in self.res]`
	`17`	`+`
	`18`	`+ # DFS Recursion, Optimized using Tuples`
	`19`	`+ def averageOfLevels2(self, root):`
	`20`	`+ self.res = []`
	`21`	`+`
	`22`	`+ def dfs(root, level):`
	`23`	`+ if not root:`
	`24`	`+ return []`
	`25`	`+ if len(self.res) == level:`
	`26`	`+ self.res.append([0,0])`
	`27`	`+ self.res[level][0] += root.val`
	`28`	`+ self.res[level][1] += 1.0`
	`29`	`+ dfs(root.left, level + 1)`
	`30`	`+ dfs(root.right, level + 1)`
	`31`	`+`
	`32`	`+ dfs(root, 0)`
	`33`	`+ return [num/count for num, count in self.res]`

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