Gate CS-2006 Question Paper With Solutions

Q. 72 Consider the C code to swap two integers and these five statements: the code

void swap(int *px, int *py)  
 {      
*px = *px - *py;    
  *py = *px + *py;  
    *px = *py - *px;  
 } 

S1 : will generate a compilation error

S2 : may generate a segmentation fault at runtime depending on the arguments

passed

S3 : correctly implements the swap procedure for all input pointers referreing to

integers stored in memory locations accessible tot he process

S4 : implements the swap procedure correctly for some but not all valid input

pointers

S5 : may add or subtract integers and pointers

(A) S1

(B) S2 and S3

(C) S2 and S4

(D) S2 and S5

Answer: (C)

Explanation: