# C Language | Set 8

• Difficulty Level : Easy
• Last Updated : 27 Mar, 2017

Following questions have been asked in GATE CS 2011 exam.

1) What does the following fragment of C-program print?

 `char` `c[] = ``"GATE2011"``; ` `char` `*p =c; ` `printf``(``"%s"``, p + p - p) ; `

(A) GATE2011
(B) E2011
(C) 2011
(D) 011

 `char` `c[] = ``"GATE2011"``; `   ` ``// p now has the base address string "GATE2011" ` `char` `*p =c;  `   `// p is 'E' and p is 'A'.   ` `// p - p = ASCII value of 'E' - ASCII value of 'A' = 4 ` `// So the expression  p + p - p becomes p + 4 which is  ` `// base address of string "2011" ` `printf``(``"%s"``, p + p - p) ;  `

2) Consider the following recursive C function that takes two arguments

 `unsigned ``int` `foo(unsigned ``int` `n, unsigned ``int` `r) { ` `  ``if` `(n  > 0) ``return` `(n%r +  foo (n/r, r )); ` `  ``else` `return` `0; ` `} `

What is the return value of the function foo when it is called as foo(513, 2)?
(A) 9
(B) 8
(C) 5
(D) 2

foo(513, 2) will return 1 + foo(256, 2). All subsequent recursive calls (including foo(256, 2)) will return 0 + foo(n/2, 2) except the last call foo(1, 2) . The last call foo(1, 2) returns 1. So, the value returned by foo(513, 2) is 1 + 0 + 0…. + 0 + 1.
The function foo(n, 2) basically returns sum of bits (or count of set bits) in the number n.

3) What is the return value of the function foo when it is called as foo(345, 10) ?

(A) 345
(B) 12
(C) 5
(D) 3