Top MCQs on Searching Algorithm with Answers

Question 1

Linear search is also called------

Random Search
Sequential search
Perfect search
None

Discuss it

Question 2

Which of the following is correct recurrence for worst case of Binary Search?

T(n) = 2T(n/2) + O(1) and T(1) = T(0) = O(1)
T(n) = T(n-1) + O(1) and T(1) = T(0) = O(1)
T(n) = T(n/2) + O(1) and T(1) = T(0) = O(1)
T(n) = T(n-2) + O(1) and T(1) = T(0) = O(1)

Discuss it

Question 3

Given a sorted array of integers, what can be the minimum worst-case time complexity to find ceiling of a number x in given array? The ceiling of an element x is the smallest element present in array which is greater than or equal to x. Ceiling is not present if x is greater than the maximum element present in array. For example, if the given array is {12, 67, 90, 100, 300, 399} and x = 95, then the output should be 100.

O(loglogn)
O(n)
O(log(n))
O(log(n) * log(n))

Discuss it

Question 4

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. }

In the above question, the correction needed in the program to make it work properly is (GATE CS 2008)

Change line 6 to: if (Y[k] < x) i = k + 1; else j = k-1;
Change line 6 to: if (Y[k] < x) i = k - 1; else j = k+1;
Change line 6 to: if (Y[k] <= x) i = k; else j = k;
Change line 7 to: } while ((Y[k] == x) && (i < j));

Discuss it

Question 5

Which of the following is the correct recurrence for the worst case of Ternary Search?

T(n) = T(n/3) + 4, T(1) = 1
T(n) = T(n/2) + 2, T(1) = 1
T(n) = T(n + 2) + 2, T(1) = 1
T(n) = T(n - 2) + 2, T(1) = 1

Discuss it

Question 6

The increasing order of performance of the searching algorithms are:

linear search < jump search < binary search
linear search > jump search < binary search
linear search < jump search > binary search
linear search > jump search > binary search

Discuss it

Question 7

The average case occurs in the Linear Search Algorithm when:

The item to be searched is in some where middle of the Array
The item to be searched is not in the array
The item to be searched is in the last of the array
The item to be searched is either in the last or not in the array

Discuss it

Question 8

Consider a sorted array of n numbers and a number x. What would be the time complexity of the best known algorithm to find a triplet with sum equal to x. For example, arr[] = {1, 5, 10, 15, 20, 30}, x = 40. Then there is a triplet {5, 15, 20} with sum 40.

O(n)
O(n^2)
O(n Log n)
O(n^3)

Discuss it

Question 9

Consider the C function given below. Assume that the array listA contains n (> 0) elements, sorted in ascending order.

int ProcessArray(int *listA, int x, int n)
{
    int i, j, k;
    i = 0;
    j = n-1;
    do
    {
        k = (i+j)/2;
        if (x <= listA[k])
            j = k-1;
        if (listA[k] <= x)
            i = k+1;
    }
    while (i <= j);
    if (listA[k] == x)
        return(k);
    else
        return -1;
}

Which one of the following statements about the function ProcessArray is CORRECT?

It will run into an infinite loop when x is not in listA.
It is an implementation of binary search.
It will always find the maximum element in listA.
It will return −1 even when x is present in listA.

Discuss it

Question 10

The average number of key comparisons done in a successful sequential search in a list of length n is

log n
(n-1)/2
n/2
(n+1)/2

Discuss it

1 2 3

There are 28 questions to complete.

Last Updated :

Take a part in the ongoing discussion

Trending in News