Recursion, Recursion

Computer Science Level 2

int y(int x) {

  if (x==0 || x==1) {

    return 1;

  } else {

    return y(x-1) + y(x-2);
  }

}

If this program returned 8, what does x equal to?

The answer is 5.

1 solution

Pranjal Jain
Apr 17, 2015

The program will return $1$ if input is $0$ or $1$ , otherwise, it will return the sum of previous two values.

So, thats a fibonacci sequence with $F_0=1$ and $F_1=1$ . This gives the sequence as $1,1,2,3,5,8$ , note that $8$ is $F_5$ and not $F_6$ as it is starting from $F_0$

Recursion, Recursion

The answer is 5.

1 solution

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