Questions and answers for exam Preparation

MCQs

Total Questions : 10

Question 1. If row-major order is used, how is the following matrix stored in memory?a b cd e fg h i

ihgfedcba
abcdefghi
cfibehadg
adgbehcfi

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Answer: Option B. -> abcdefghi

It starts with the first element and continues in the same row until the end of row is reached and then proceeds with the next row. C follows row-major order.

Question 2. What is a sorted array?

Arrays sorted in numerical order
Arrays sorted in alphabetical order
Elements of the array are placed at equally spaced addresses in the memory
All of the mentioned

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Answer: Option D. -> All of the mentioned

The array can be sorted in any way, numerical, alphabetical or any other way but the elements are placed at equally spaced addresses.

Question 3. Choose the appropriate code that counts the number of non-zero(non-null) elements in the sparse array.

public int count(){ int count = 0; for (List cur = this.next; (cur != null); cur = cur.next) { count++; } return count;}
public int count(){ int count = 0; for (List cur = this; (cur != null); cur = cur.next) { count++; } return count;}
public int count(){ int count = 1; for (List cur = this.next; (cur != null); cur = cur.next) { count++; } return count;}
None of the mentioned

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Answer: Option A. -> public int count(){ int count = 0; for (List cur = this.next; (cur != null); cur = cur.next) { count++; } return count;}

A simple 'for loop' to count the non-null elements.

Question 4. Which of the following performs the fetch operation?

public Object fetch(int index){ List cur = this.next; Object val = null; while (cur != null && cur.index != index) { cur = cur.next; } if (cur != null) { val = cur.val; } else { val = null; } return val;}
public Object fetch(int index){ List cur = this; Object val = null; while (cur != null && cur.index != index) { cur = cur.next; } if (cur != null) { val = cur.val; } else { val = null; } return val;}
public Object fetch(int index){ List cur = this; Object val = null; while (cur != null && cur.index != index) { cur = cur.index; } if (cur != null) { val = cur.val; } else { val = null; } return val;}
None of the mentioned

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Answer: Option B. -> public Object fetch(int index){ List cur = this; Object val = null; while (cur != null && cur.index != index) { cur = cur.next; } if (cur != null) { val = cur.val; } else { val = null; } return val;}

You travers through the array until the end is reached or the index is found and return the element at that index, null otherwise.

Question 5. To search for an element in a sorted array, which searching technique can be used?

Linear Search
Jump Search
Binary Search
Fibonacci Search

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Answer: Option C. -> Binary Search

Since the array is sorted, binary search is preferred as its time complexity is O(logn).

Question 6. Identify the disadvantages of bit array.

Without compression, they might become sparse
Accessing individual bits is expensive
Compressing bit array to byte/word array, the machine also has to support byte/word addressing
All of the mentioned

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Answer: Option D. -> All of the mentioned

Without compression, they become sparse in both time and space, also if random access is more common than sequential access, then they have to be compressed to byte/word array.

Question 7. Which of the following is an advantage of bit array?

Exploit bit level parallelism
Maximal use of data cache
Can be stored and manipulated in the register set for long periods of time
All of the mentioned

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Answer: Option D. -> All of the mentioned

Because bit arrays are compact, they outperform many other data structures.

Question 8. Which of the following is the correct syntax to declare an ArrayList in Java?

ArrayList al = new ArrayList();
ArrayList al = new ArrayList[];
ArrayList al() = new ArrayList();
ArrayList al[] = new ArrayList[];

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Answer: Option A. -> ArrayList al = new ArrayList();

This is a non-generic way of creating an ArrayList.

Question 9. What does the following piece of code do?for(int i = 0; i < row; i++){ for(int j = 0; j < column; j++) { if(i == j) sum = sum + (array[i][j]); }}System.out.println(sum);