Gate CS-2006 Question Paper With Solutions

Q. 71 Consider these two functions and two statements S1 and S2 about them

int work1(int *a, int i, int j) 
 {    
  int x = a[i+2];   
   a[j] = x+1;   
   return a[i+2] – 3;  }     int work2(int *a, int i, int j) 
 {   
   int t1 = i+2;      int t2 = a[t1];      a[j] = t2+1;   
   return t2 – 3; 
 } 

S1 : The transformation from work 1 to work 2 is valid, i.e., for any program state and input arguments, work 2 will compute the same output and have the same effect on program state as work 1 S2 : All the transformations applied to work 1 to get work 2 will always improve the performance (i.e. reduce CPU time) of work 2 compared to work 1

(A) S1 is false and S2 is false

(B) S1 is false and S2 is true

(C) S1 is true and S2 is false

(D) S1 is true and S2 is true

Answer: (A)

Explanation: