binary tree

Question

The height of a binary tree having $`\text{i’}$ nodes at level $`\text{i’}$ considering root to be at level $1$ is __________, where $`n\text{’}$ is the total no. of nodes in the tree.

• A. $O(\log n)$
• B. $(O(n)$
• C. $O(\sqrt{n})$
• D. $O(n^{2})$

Answer 1

say n nodes are in binary tree.

1+2+3+4+...+i=n

   (i*(i+1)) / 2 = n

                i²=n

height is=O($\sqrt{n}$ )