# Sum of all nodes in Binary Tree

EasyGiven a binary tree that contains nodes with numbers, calculate the sum of all the nodes in the tree.

For example, let's say you're given the following binary tree:

Your fuction should return

`27`

, the sum of all nodes.## Try it

## Solution

## 9 Essential Trees & Graphs Coding Interview Problems

Master Trees & Graphs by trying the coding challenges below.

- 1.Inorder TraversalEasy
- 2.Tree SumEasy
- 3.Tree HeightEasy
- 4.LCAMedium
- 5.Max Path SumHard
- 6.Search mazeMedium
- 7.Number of islandsMedium
- 8.Kth SmallestMedium
- 9.Sort K ArraysHard