1
GATE CSE 2008
MCQ (Single Correct Answer)
+2
-0.6
We have a binary heap on n elements and wish to insert n more elements (not necessarily one after another) into this heap. The total time required for this is
A
$$\Theta(\log n)$$
B
$$\Theta(n)$$
C
$$\Theta(n\log n)$$
D
$$\Theta(n^2)$$
2
GATE CSE 2008
MCQ (Single Correct Answer)
+2
-0.6
The subset-sum problem is defined as follows:
Given a set S of n positive integers and a positive integer W, determine whether there is a subset of S Whose elements sum to W. An algorithm Q solves this problem in O(nW) time. Which of the following statements is false?
A
Q solves the subset-sum problem in polynomial time when the input is encoded in unary
B
Q solves the subset-sum problem in polynomial time when the input is encoded in binary
C
The subset sum problem belongs to the class NP
D
The subset sum problem is NP-hard
3
GATE CSE 2008
MCQ (Single Correct Answer)
+2
-0.6
Consider the following C program that attempts to locate an element x in an array Y[] using binary search. The program is erroneous.
1.   f(int Y[10], int x) {
2.     int i, j, k;
3.     i = 0; j = 9;
4.     do {
5.             k =  (i + j) /2;
6.             if( Y[k] < x)  i = k; else j = k;
7.         } while(Y[k] != x && i < j);
8.     if(Y[k] == x) printf ("x is in the array ") ;
9.     else printf (" x is not in the array ") ;
10.  }
The correction needed in the program to make it work properly is
A
Change line 6 to: if (Y[k]
B
Change line 6 to: if (Y[k]
C
Change line 6 to: if (Y[k]
D
Change line 7 to: } while ((Y[k]==x)&&(i
4
GATE CSE 2008
MCQ (Single Correct Answer)
+2
-0.6
Consider the following C program that attempts to locate an element x in an array Y[] using binary search. The program is erroneous.
1.   f(int Y[10], int x) {
2.     int i, j, k;
3.     i = 0; j = 9;
4.     do {
5.             k =  (i + j) /2;
6.             if( Y[k] < x)  i = k; else j = k;
7.         } while(Y[k] != x && i < j);
8.     if(Y[k] == x) printf ("x is in the array ") ;
9.     else printf (" x is not in the array ") ;
10.  }
On which of the following contents of Y and x does the program fail?
A
Y is [1 2 3 4 5 6 7 8 9 10] and x < 10
B
Y is [1 3 5 7 9 11 13 15 17 19] and x < 1
C
Y is [2 2 2 2 2 2 2 2 2 2] and x > 2
D
Y is [2 4 6 8 10 12 14 16 18 20] and 2 < x < 20 and x is even