Algorithm, pseudocode, and program are three related terms in computer programming. The difference between an algorithm and a pseudocode is algorithm is an informal representation of a solution to a problem whereas, a pseudocode acts as a bridge between an algorithm and a program. From the algorithm it is easier to convert into pseudocode and using pseudocode it is simpler to convert into language-specific code. A program is an exact code written for solving a problem in a given programming language.
What is an Algorithm?
An algorithm consists of a sequence of steps that are designed to be executed in a specific order to solve a particular problem or achieve a specific task. Algorithms are essential in computer science and programming as they provide a structured way to solve problems and perform computations.
The instructions of an algorithm may include various operations like arithmetic calculations, loops, conditional statements, and more, to be executed in methodical and logical order.
The selection of the algorithm depends on the characteristics of the problem. The problem is first analyzed to select the best algorithm or write a new algorithm to solve it.
Let us see an algorithm to find the sum of all even numbers within a given range [0,N]
- Initialize a variable sum to 0.
- Iterate through numbers from start to end.
- For each number, check if it’s even (i.e., divisible by 2).
- If it’s even, add it to the sum.
- After the loop, return sum.
What is a Pseudocode?
Pseudocodes are a way to represent an algorithm to solve a problem in a human-readable form. It is a mixture of natural language and a program-like structure that helps developers and analysts write code in a particular programming language. Pseudo code is not executable and is not equivalent to a real programming language.
Pseudo codes are written in plain English with programming language control structures such as loops (while loop, for loop), if-then-else, repeat-until, etc. They don’t have any strict syntax and are flexible. Pseudocode is often written similarly to the programming languages like C++, FORTRAN, etc.
Pseudocode to find the sum of all even numbers within a given range [0,N]
function sum_of_evens(start, end):
sum = 0 # Initialize the sum to zero
for num from start to end:
If num is even: # Check if the current number is even
sum = sum + num # Add the even number to the sum
Return sum # Return the final sum
What is a Program?
With the help of pseudo code and algorithms, developers write a program that computers understand and execute. The written program requires compilers or interpreters to convert the high-level code into machine-understandable language.
A program is a sequence of instructions given by a programmer to the computer to be performed in a given logical order to execute a task or find a solution to a problem. There are many different programming languages such as C, C++, Java, Python, Scala, Swift, etc.
Program in Java to find the sum of all even numbers within a given range [0,N]
import java.util.Scanner;
public class SumOfEvensInRange {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
// Input the upper limit of the range
System.out.print("Enter the upper limit (N): ");
int N = scanner.nextInt();
// Initialize the sum to zero
int sum = 0;
// Iterate through numbers from 0 to N
for (int num = 0; num <= N; num++) {
// Check if the current number is even
if (num % 2 == 0) {
// Add the even number to the sum
sum += num;
}
}
// Display the sum of even numbers within the range
System.out.println("The sum of even numbers from 0 to " + N + " is: " + sum);
// Close the scanner
scanner.close();
}
}
Algorithm vs Pseudocode vs Program
Let us now compare the algorithm, pseudocode, and program:
| Feature | Algorithm | Pseudocode | Program |
|---|---|---|---|
| Definition | A set of steps of a problem-solving procedure or method. | A high-level representation of an algorithm using a mixture of technical format and human-readable text. | A set of instructions written for computers in a particular programming language to implement an algorithm or pseudocode. |
| Formality | Generally, it’s a more abstract and informal concept, not tied to a particular programming language or syntax. | Less formal than code but more structured than plain language. It uses common language elements and keywords. | A formal representation of the algorithm using a specific programming language with precise syntax and rules that are understandable to the compiler or interpreter. |
| Language Neutrality | Language-neutral; can be expressed in plain language or pseudocode. | Language-neutral; it aims to be easily understood by humans as well as easily converted into code in any programming language. | Language-specific; written in a particular programming language with syntax and conventions specific to that language. |
| Execution | Not directly executable; it’s a plan for solving a problem. | Not executable on its own; it provides a high-level overview of the solution’s logic. We can use it for a dry run. | Executable by a computer; it can be compiled or interpreted to produce a functioning program. |
| Syntax | No specific syntax rules; described in plain language or a diagram. | Uses structured language constructs like loops, conditionals, and functions but without strict syntax rules. | Must adhere to the precise syntax and rules of the chosen programming language. |
| Usage | Used for planning, design, and communication of problem-solving approaches. | Used for communicating and documenting an algorithm before writing code. | Used for actual execution and solving the problem at hand. |
FAQs
Q. How are algorithms and pseudocode related?
A. Pseudocode is a way to represent an algorithm in a more structured and human-readable format, making it easier to understand before implementing it in a programming language.
Q. How do pseudocode and programs differ?
A. Pseudocode is a high-level description of an algorithm, while a program is the actual implementation of that algorithm in a specific programming language.
Conclusion
- An algorithm is designed during the designing and planning phase. It is a set of instructions for solving a problem or performing some computations.
- Pseudo code is language-neutral code like an informal set of steps that can be converted into code of any programming language.
- A program is a set of instructions written for a machine to find a solution to a problem. It is language-specific and can be written in C, C++, Python, Java, etc.
- Algorithm and Pseudocode are informal whereas a program is a formal representation of the solution.
- Algorithm and Pseudocode are not executable but a program can be executed to find the solution using compilers and interpreters.
