GATE CSE 2015 Set 3 | Question: 39

Question

Consider the following recursive C function.

void get(int n)
{
    if (n<1) return;
    get (n-1);
    get (n-3);
    printf("%d", n);
}

If $get(6)$ function is being called in $main()$ then how many times will the $get()$ function be invoked before returning to the $main()$?

• A. $15$
• B. $25$
• C. $35$
• D. $45$

Comments

Best explanation: https://www.geeksforgeeks.org/gate-gate-cs-2015-set-3-question-49/

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How can  get(1) call to get(0) and get(-2) as n<1 ?.

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T(n) = T(n-1) + T(n-3) +1
T(0) = 1 (counting get(0) as 1 count)
T(1) = 3
T(-1) = 1 (count get(-1) as 1 count)

solving T(6) in this will also give 25

Answer 1

http://www.geeksforgeeks.org/gate-gate-cs-2015-set-3-question-49/

nicely explained

Comments

can u explain what they hav done ?? i am nt getting it ..