ECM 1414 Introduction to Algorithms

Question 1

[Sedgewick 2011]

Answer 1

The term algorithm is used in computer science to describe methods for solving problems that are suited for computer implementation.

Question 2

[Aho, Hopcroft & Ulman 1975]

Answer 2

An algorithm is a finite sequence of instructions, each of which has a clear meaning and can be performed with a finite amount of effort in a finite length of time

Question 3

[Wikipedia]

Answer 3

An algorithm is an effective method expressed as a finite list of well-defined instructions for calculating a function.

Question 4

[Levitin 2003]

Answer 4

An algorithm is a finite sequence of unambiguous instructions for solving a problem, i.e., for obtaining the required output for any legitimate input in a finite amount of time.

Question 5

Some try to classify algorithms according to the problem-solving approach they use:

Answer 5

• Iterative Algorithms
• Direct/Indirect Recursive Algorithms
• Divide-and-conquer Algorithms
• Dynamic Programming Algorithms
• Randomised Algorithms
• Brute-Force Algorithms

Question 6

3 simple algorithms

Answer 6

Consecutive Integer Checking
GCD
Middle school procedure

Question 7

The need to study algorithms

Answer 7

• Computer programs would not exist without algorithms. So even if you’re not a computer science student, you’d benefit from the study of algorithms given the ubiquity of computer programs.
• Development of your analytical skills. Algorithms are special kind of solutions to problems: they are not answers but well-defined steps for getting answers