Steps of Problem Solving and Algorithms

Steps of Problem Solving and Algorithms

Before writing any program we first understand the problem. Every program follows the input → process → output cycle: it takes data in, works on it, and gives a result. Solving a problem on a computer has four steps:

1. Analyse the problem: what is given (input) and what is asked (output)?
2. Develop an algorithm: write the exact steps in plain language.
3. Code: turn the algorithm into a program, here in Python.
4. Test and debug: run the program on sample inputs and fix the mistakes.

An algorithm is a finite, ordered set of clear steps that solves a problem. A good algorithm has a definite start and end, takes an input, gives an output, and every step is unambiguous. For example, an algorithm to find the average of three numbers:

Step 1: Start
Step 2: Read three numbers A, B and C
Step 3: SUM = A + B + C
Step 4: AVG = SUM / 3
Step 5: Print SUM and AVG
Step 6: Stop

In Python each step becomes one line. Here is the same algorithm for two numbers; notice how each line of code matches one step.

a, b = map(int, input().split())
total = a + b
print("Sum =", total, "Average =", total / 2)

a, b, c = map(int, input().split())
total = 0  # Step 3: add the three numbers
print("Sum =", total, "Average =", total / 3)