Problem Solving in Computer Science

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Questions and Answers

What are the three basic building blocks used to construct algorithms?

Sequence, selection, and iteration.

How does control flow operate in programming?

Control flow executes individual statements in a specific order, using sequence, selection, and iteration.

Explain what a statement is in the context of algorithms.

A statement is a single action performed by a computer, such as inputting, processing, or outputting data.

Describe the concept of selection in algorithms.

Selection allows the program to execute different instructions based on whether a condition is true or false. Signup and view all the answers

What does iteration refer to in the context of algorithms?

Iteration refers to executing a set of statements repeatedly based on a specified condition. Signup and view all the answers

Write a simple algorithm to add two numbers using sequence.

Step 1: Start; Step 2: get a, b; Step 3: calculate c=a+b; Step 4: Display c; Step 5: Stop. Signup and view all the answers

What is the result of the conditional test in a selection statement?

The result determines which part of the program executes based on the truth value of the condition. Signup and view all the answers

In the context of algorithms, what is meant by the term 'state'?

State refers to the transition from one process to another under specified conditions within a given time. Signup and view all the answers

What are the basic building blocks of an algorithm?

The basic building blocks of an algorithm are statements, state, control flow, and functions. Signup and view all the answers

How does problem solving start and end in a systematic approach?

Problem solving starts with problem specifications and ends with a correct program. Signup and view all the answers

What are some common techniques used in problem solving?

Common techniques include algorithms, flowcharts, pseudo codes, and program implementations. Signup and view all the answers

List two properties that an algorithm must possess.

An algorithm should be precise and unambiguous, and it should conclude after a finite number of steps. Signup and view all the answers

Why is accuracy important when evaluating algorithms?

Accuracy is important because some algorithms may yield more precise results than others for the same problem. Signup and view all the answers

Explain what is meant by 'termination' in the context of algorithms.

Termination refers to an algorithm concluding after a finite number of steps, ensuring that it does not run indefinitely. Signup and view all the answers

What strategy can be used to solve problems like finding the minimum in a list?

A simple iteration strategy can be used to compare elements and find the minimum in a list. Signup and view all the answers

What is a quality that can improve an algorithm's efficiency?

A quality that can improve efficiency is minimizing the time and memory required to execute the program. Signup and view all the answers

Study Notes

Problem Solving

Problem solving is a process to define a problem and create solutions.
The process starts with the problem specifications and ends with a working program.

Problem Solving Techniques

Problem solving techniques are methods to provide logic for solving a problem.
Algorithms, flowcharts, pseudo code, and programs are all representations of problem solving techniques.

Algorithm

An algorithm is a sequence of instructions that describes a method for solving a problem.
It's a step by step procedure for solving a problem.
Properties of algorithms:
- Written in clear English.
- Instructions are unambiguous.
- No infinite repetition of instructions.
- Finishes in a finite number of steps.
- Has a clear end point.
- Results are obtained only after algorithm termination.

Qualities of a Good Algorithm

Time: The time it takes to execute a program. Less time is better.
Memory: The amount of computer memory a program uses. Less memory is better.
Accuracy: Some algorithms may provide more accurate results than others for the same problem.

Example Algorithm: Print "Good Morning"

Start
Print "Good Morning"
Stop

Building Blocks of Algorithms

Algorithms are built from three basic blocks:
- Sequence
- Selection
- Iteration

Statements

A statement represents a single action in a program.
Examples of statements include:
- Inputting data (providing information to the program)
- Processing data (performing operations on the input)
- Outputting data (displaying the processed result)

State

A state is a transition from one process to another process under a specific condition within a given time.

Control Flow

Control flow is the order in which statements are executed.
Three types of control flow:
- Sequence
- Selection
- Iteration

Sequence

Instructions are executed one after another.

Example: Add Two Numbers

Start
Get two numbers, a and b
Calculate c = a + b
Display c
Stop

Selection

A selection statement allows the program to execute different parts of code based on a condition.
If the condition is true, one part of the code is executed.
If the condition is false, a different part of the code is executed.

Example: Check Voter Eligibility

Start
Get the user's age
If the age is greater than or equal to 18, print "Eligible to vote"
Otherwise, print "Not eligible to vote"
Stop

Iteration

Iteration, or looping, executes a set of statements repeatedly based on a condition.
These set of statements are executed more than one time.

Example: Print Natural Numbers Up To N

Start
Get the value of n
Initialize i = 1
While (i <= n)
- Print i
- Increment i by 1
Stop

What is not Included in the Summary:

The text also discusses notation such as pseudo code, flowcharts, and programming language.
It also covers simple strategies for developing algorithms like iteration and recursion.
This information is not included in the summary to keep it concise.

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Description

This quiz covers foundational concepts in problem solving, including techniques and algorithms. Learn about the qualities of a good algorithm and how to effectively define and solve problems using structured methods. Test your knowledge of key principles that guide the programming process.