# Preorder Binary Tree

Easy
0/40
Average time to solve is 10m
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## Problem statement

You are given a ‘Binary Tree’.

Return the preorder traversal of the Binary Tree.

Example:
``````Input: Consider the following Binary Tree:
``````

``````Output:
Following is the preorder traversal of the given Binary Tree: [1, 2, 5, 3, 6, 4]
``````

Detailed explanation ( Input/output format, Notes, Images )
##### Sample Input 1:
``````1 2 3 5 4 6 7 -1 -1 -1 -1 -1 -1 -1 -1
``````

##### Sample Output 1:
``````1 2 5 4 3 6 7
``````

##### Explanation of Sample Input 1:
``````The Binary Tree given in the input is as follows:
``````

##### Sample Input 2:
``````5 6 10 2 3 -1 -1 -1 -1 -1 9 -1 -1
``````

##### Sample Output 2:
``````5 6 2 3 9 10
``````

##### Explanation of Sample Input 2:
``````The Binary Tree given in the input is as follows:
``````

##### Expected Time Complexity:
``````Try to do this in O(n).
``````

##### Constraints:
``````1 <= n <= 100000
where 'n' is the number of nodes in the binary tree.

Time Limit: 1 sec
``````
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