Gate CS-2016-2 Question Paper With Solutions

Q. 45 The following function computes X^Y for positive integers X and Y.

int exp(int X, int Y)  {      int res = 1, a = X, b = Y;      while ( b != 0 )      {          if ( b%2 == 0)          {              a = a*a;              b = b/2;          }          else         {              res = res*a;              b = b-1;          }      }      return res;  } 

Which one of the following conditions is TRUE before every iteration of the loop

Answer: (C)

Explanation: