# How to calculate size of binary tree

This is a continuation of my post How to create a binary tree in c#.In this post, I will show you how to find the size of the binary tree.

Size of the binary tree is the number of nodes in a given tree.

Following is the recursive implementation of size function

  //Compute the number of nodes in a tree.
public int Size()
{
return Size(_root);
}
private int Size(Node root)
{
if (root == null)
return 0;
return 1 + Size(root.Left) + Size(root.Right);
}


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