Yahoo Interview Question: Write a function given x, the... | Glassdoor

Interview Question

Intern Interview(Student Candidate) Sunnyvale, CA

Write a function given x, the function returns the xth

  number in the Fibonacci sequence.

Interview Answer

4 Answers


int getNthFib(int n) {
// assume n is positive
if (n <= 2) return n;
int i = 1;
int j = 2;
int k;
count = 2;
while (count < n) {
  k = i + j:
  count ++;
  i = j;
  j = k;
return k;

HappyCoder on Nov 2, 2009

I've been asked this question several times at interviews, and it's usually associated with recursion, so the answer most would like to see is like:

int getFib(int n) {
    return n <= 1 ? n : getFib(n - 1) + getFib(n - 2);

The interviewer will also want to know you understand that recursion would be slow for high values of n.

Anonymous on Dec 13, 2009

Prior to your next interview, I would also google "tail recursion" and demonstrate how more efficient a tail recursive fibonacci sequence would be.

Anonymous on Dec 14, 2009

using namespace std;

int getFib(int n) {
    if(n==1||n==2) return n;
    return getFib(n-1)+getFib(n-2);

int main(){
    int n=6;

HarishIITR on Jan 11, 2012

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