Friday, July 24, 2026
HomeData Modelling & AIAlgorithms | Analysis of Algorithms (Recurrences) | Question 9

Algorithms | Analysis of Algorithms (Recurrences) | Question 9

The time complexity of the following C function is (assume n > 0 (GATE CS 2004)




int recursive (mt n)
{
   if (n == 1)
     return (1);
   else
     return (recursive (n-1) + recursive (n-1));
}


(A) 0(n)
(B) 0(nlogn)
(C) 0(n^2)
(D) 0(2^n)

Answer: (D)
Explanation: Recursive expression for the above program will be.

  T(n) = 2T(n-1) + c
  T(1) = c1.

Let us solve it.

  T(n) = 2(2T(n-2) + c) + c        = 4T(n-2) + 3c
  T(n) = 8T(n-3) + 6c + c          =  8T(n-3) + 7c
  T(n) = 16T(n-4) + 14c + c        =  16T(n-4) + 15c
  ............................................................
  .............................................................
  T(n) = (2^(n-1))T(1) +  (2^(n-1) - 1)c

  T(n) = O(2^n)

Quiz of this Question

Whether you’re preparing for your first job interview or aiming to upskill in this ever-evolving tech landscape, neveropen Courses are your key to success. We provide top-quality content at affordable prices, all geared towards accelerating your growth in a time-bound manner. Join the millions we’ve already empowered, and we’re here to do the same for you. Don’t miss out – check it out now!
RELATED ARTICLES

4 COMMENTS

Most Popular

Dominic
32520 POSTS0 COMMENTS
Milvus
131 POSTS0 COMMENTS
Nango Kala
6902 POSTS0 COMMENTS
Nicole Veronica
12017 POSTS0 COMMENTS
Nokonwaba Nkukhwana
12115 POSTS0 COMMENTS
Shaida Kate Naidoo
7023 POSTS0 COMMENTS
Ted Musemwa
7265 POSTS0 COMMENTS
Thapelo Manthata
6980 POSTS0 COMMENTS
Umr Jansen
6971 POSTS0 COMMENTS