Basic Questions and Answers on Algorithms

1. Define Algorithm.

An algorithm is a sequence of unambiguous instructions for solving a problem in a finite amount of time.

2.Write a short note on Algorithm Design and Analysis of Process.

o Understand the problem

o Decide onComputational DeviceExact Vs Approximate Algorithms

o Algorithm Design Techniques

o Design an algorithms

o Prove Correctness

o Analyze the Algori thm

o Code the Algorithm

3. What are the 2 kinds of Algorithm Efficiency

Time Efficiency-How fast your algorithm runs?

Space Efficiency-How much extra memory your algorithm needs?

 4. How can you specify Algorithms?

Algorithms can be specified natural language or pseudo code. 

5. What is Pseudo Code?

Pseudo Code is a mixture of Natural Language and Programming Language Constructs such as functions, loops, decision making statements..etc

6. What are the Important Problem Types?

• Sorting

• Searching

• String Processing

• Graph Problem

• Combinatorial Problem

• Geometric Problem

• Numerical Problem

7.How can you Classify Algorithms

Among several ways to classify algorithms, the 2 principal alternatives are

• To group algorithms according to types of problem they solve com

• To group algorithms according to underlying design techniques they are based upon

8. What is Sorting Problem?

Sorting algorithm is rearrange the items of given list descending/ascending order. Sorting algorithms classified into

• Stable Sorting Algorithm

• Non-Stable Algorithm

9.What is Searching Problem?

Finding a given value, called search key given set.  Searching Algorithms needs more

memory space   and sorted array.

10. What is Graph Problem?

Graph is a collection of dg s and vertices. G=(V,E). For e.g. Traversal Algorithms, Shortest

Path Algorithm, Graph Colouring Problem

11. What is Combinatorial  Problem.

This problem that ask to find combinatorial object such as permutations, combinations or a

subset. Combinatorial problems are most difficult to solve. For eg Travelling sales man

problem

12. Differentiate Time Efficiency and Space Efficiency?

Time Efficiency measured by counting the number of times the algorithms basic operation is executed. Space Efficiency is measured by counting the number of extra memory units consumed by the algorithm.

13. What are the features of efficient algorithm?

• Free of ambiguity

• Efficient in execution time

• Concise and compact Completeness

• Definiteness Finiteness

14.Define Order of Algorithm

The order of algorithm is a standard notation of an algorithm that has been developed to represent function that bound the computing time for algorithms.The order of an algorithm is a way of defining its efficiency. It is usually referred as O-notation

15.  Define Big Omega Notation.

Omega notation provides lower bound for the function t

A function t(n) is said to Omega (g(n)), if there exist some.positive constant C and some non negative integer N0, such that

t(n)>=Cg(n) for all n>=n0 

     16.What is Big ‘Oh’     

               Notation.

The Big ‘Oh’ notation provides an upper bound for the function t.A function t(n) is said to be O(g(n)), if there exist some positive constant C and some non negative number,suchthat, t(n)<=Cg(n), for all n>=no

17. What are the different types of time complexity?

The time complexity can be classified into 3 types, they are

• Worst case analysis

• Average case analysis

• Best case analysis

18.How the algorithm’s time efficiency is measured.

Time efficiency indicates how fast an algorithm runs. Time taken by a program to complete its task depends on the number of steps in an algorithm.

The time taken by an algorithm is the sum of compile time and execution time. The compile time does not depend on the instance characteristics