# Algorithms: Question Set – 04

#### Define Program.

A computer algorithm gets “translated” into a programming language to take the form of a programme. It’s not uncommon to hear phrases like “procedure,” “function,” and “subroutine” used interchangeably with “programme.”

#### What are the different criteria used to improve the effectiveness of algorithm?

(i) The effectiveness of algorithm is improved, when the design, satisfies the following constraints to be minimum.

• Time efficiency – how fast an algorithm in question runs.
• Space efficiency – an extra space the algorithm requires

(ii) The algorithm has to provide result for all valid inputs.

#### How will you measure input size of algorithms?

• The amount of time an algorithm needs to complete its task is proportional to the magnitude of the data it receives.
• So the execution time of the programme relies on the size of its input.
• The size of the input is indicated by the parameter n, which is the number of items in the input; this number is used to calculate the size of the input for the algorithm.

#### Give the two major phases of performance evaluation

Performance evaluation can be loosely divided into two major phases:

• A prior estimates (performance analysis)
• A Posterior testing (performance measurement)

#### Define input size.

When referring to a particular instance of a problem, the “input size” is defined as the number of words (or the number of items) that are required to adequately explain that particular case.

#### Define the terms: pseudocode, flow chart

• A natural language is combined with structures that are similar to those found in programming languages to create a pseudocode.
• Pseudocodes are typically capable of higher levels of precision than natural languages.
• A flowchart is a method of expressing an algorithm that consists of a collection of connected geometric shapes that contain descriptions of the steps that are involved in the algorithm.

#### Define the divide an conquer method.

• The divide-and-conquer technique advises, when presented with a function to compute on ‘n’ inputs, breaking those inputs into ‘k’ separate subsets, where 1 < k < n, which results in ‘k’ subproblems.
• After each of the subproblems has been addressed, a strategy for combining the individual solutions into a whole-problem solution needs to be developed.
• It is possible to reapply the divide-and-conquer technique if the individual problems still constitute a sizeable portion of the overall issue.

#### What do you mean by Combinatorial Problem?

Combinatorial problems are questions that challenge you to find a combinatorial item (such a permutation, a combination, or a subset) that fulfils certain restrictions and has some desired attribute. These problems can be broken down into three categories: