Top 50 Algorithms MCQs with Answers

Question 41

The time taken by binary search algorithm to search a key in a sorted array of n elements is

• O ( log₂n )

• O ( n )

• O ( n log₂n )

• O ( n^2)

Question 42

Match the following:

List - I	List - II
(a) Sequential Search	(i) Dynamic programming principle
(b)Branch - and - bound	(ii) repeatedly double index
(c) Exponential Search	(iii) O(LogN)
(d) Binary Search	(iv)O(N)

codes:

	(a)	(b)	(c)	(d)
(1)	(i)	(iv)	(iii)	(ii)
(2)	(iv)	(i)	(ii)	(iii)
(3)	(i)	(iv)	(ii)	(iii)
(4)	(iv)	(ii)	(i)	(iii)

• (1)

• (2)

• (3)

• (4)

Question 43

Number of comparisons required for an unsuccessful search of an element in a sequential search, organized, fixed length, symbol table of length L is

• L
• L/2
• (L+1)/2
• 2L

Question 44

The necessary condition for using binary search in an array is :-

• The array should not be too long

• The array should of more size

• The array should be sorted 

• None of these

Question 45

Consider the following C program that attempts to locate an element x in an array Y[] using binary search. The program is erroneous. (GATE CS 2008) 

C

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?

• Y is [1 2 3 4 5 6 7 8 9 10] and x < 10

• Y is [1 3 5 7 9 11 13 15 17 19] and x < 1

• Y is [2 2 2 2 2 2 2 2 2 2] and x > 2

• Y is [2 4 6 8 10 12 14 16 18 20] and 2 < x < 20 and x is even