Question

What is the time complexity of the above recursive implementation used to reverse a string?

(a) O(1)

(b) O(n)

(c) O(n^2)

(d) O(n^3)

The question was asked in an internship interview.

This key question is from String Reversal using Recursion in section Recursion of Data Structures & Algorithms II

Answer 1

Right choice is (b) O(n)

For explanation: The time complexity of the above recursive implementation used to reverse a string is O(n).