Programming

1. Algorithm Design

Before writing code, algorithms are designed using two techniques:

• Flowcharts: Graphical logic mapping using standard symbols: Terminal (Oval), Input/Output (Parallelogram), Process (Rectangle), Decision (Diamond), and Flowlines (Arrows).
• Pseudo-code: A human-readable text-based description of logic, structured using keywords like IF-THEN-ELSE or WHILE.

2. Python Control Structures

Python scripts execute code through three structures:

1. Sequence: Executing lines of code one after another.
2. Selection (if-elif-else):

   score = int(input("Enter marks: "))
   if score >= 75:
       grade = "A"
   elif score >= 65:
       grade = "B"
   else:
       grade = "C"
   print("Grade:", grade)

3. Iteration (Looping):

   # Printing even numbers from 2 to 10
   for i in range(2, 11, 2):
       print(i)

3. Python Data Structures

• List: Ordered, mutable collection. Written with square brackets.numbers = [10, 20, 30]
• Tuple: Ordered, immutable collection. Written with parentheses.point = (4, 5)
• Dictionary: Key-value store. Unordered and mutable.student = {"name": "Ranindu", "index": 4810}