CP143: Recursion and Advanced Function Concepts

Good day, good people! Welcome to the Recursion practice exercises for CP143.

📚 Module Information

Course: CP143 - Computer Programming Institution: Stellenbosch University Topic: Recursion and Advanced Function Concepts Lecture Coverage: Lecture 12 Textbook: Chapter 5 (sections 5.13-5.16) Learning Outcomes: LO2 (Design efficient algorithms), LO5 (Control structures - recursion)

🎯 Learning Objectives

By completing these exercises, you will:

• Understand recursive problem solving (base case + recursive step)
• Implement classic recursive algorithms
• Trace recursive execution and call stacks
• Compare recursive vs iterative solutions
• Apply recursion to strings, arrays, and mathematical problems

Overview

This repository contains 5 practice exercises designed to help you master recursion in C. Each exercise focuses on different aspects of recursive thinking and implementation.

📋 Exercises

Exercise 1: Recursive Sum and Product (⭐ Easy)

File: Exercise_01/exercise_1.c

Write recursive functions to calculate sum and product of numbers 1 to n

Exercise 2: Palindrome Checker (⭐ Easy)

File: Exercise_02/exercise_2.c

Check if a string is a palindrome using recursion

Exercise 3: Recursive Array Search (⭐⭐ Medium)

File: Exercise_03/exercise_3.c

Implement linear search recursively

Exercise 4: GCD - Euclidean Algorithm (⭐⭐ Medium)

File: Exercise_04/exercise_4.c

Find greatest common divisor using the Euclidean algorithm

Exercise 5: Binary to Decimal Conversion (⭐⭐⭐ Hard)

File: Exercise_05/exercise_5.c

Convert binary strings to decimal numbers recursively

🚀 Getting Started

Option 1: GitHub Codespaces (Recommended)

Click the button below to open this repository in a fully configured cloud development environment:

Why Codespaces?

• ✅ No setup required - works in your browser
• ✅ Pre-configured C compiler and debugger
• ✅ Consistent environment across all devices
• ✅ Free tier available (60 hours/month)
• ✅ Access from anywhere with internet

Option 2: Local Development

Clone the repository:

git clone https://github.com/SwiftTuition/CP143-Recursion-and-Advanced-Functions.git
cd CP143-Recursion-and-Advanced-Functions

💻 How to Compile

Each exercise can be compiled using GCC:

gcc exercise_1.c -o exercise_1
gcc exercise_2.c -o exercise_2
gcc exercise_3.c -o exercise_3
gcc exercise_4.c -o exercise_4
gcc exercise_5.c -o exercise_5

Or if you're in an exercise folder:

cd Exercise_01
gcc exercise_1.c -o exercise_1

How to Run

After compiling, run the executable:

./exercise_1
./exercise_2
./exercise_3
./exercise_4
./exercise_5

On Windows:

exercise_1.exe
exercise_2.exe
exercise_3.exe
exercise_4.exe
exercise_5.exe

Tips for Success

1. Identify the Base Case: Every recursive function needs a terminating condition
2. Define the Recursive Step: How does the problem get smaller with each call?
3. Trust the Recursion: Assume the recursive call works for smaller inputs
4. Trace Your Code: Use pencil and paper to trace through recursive calls
5. Test Edge Cases: Try n=0, n=1, empty strings, etc.

Common Mistakes to Avoid

• Forgetting the base case (causes infinite recursion and stack overflow)
• Incorrect base case (function never terminates)
• Not making progress toward the base case
• Modifying parameters incorrectly
• Stack overflow from too many recursive calls

Getting Help

If you're stuck:

1. Read the problem description carefully in each exercise's README.md
2. Review the theory and examples from the learning package
3. Trace through the recursion with small inputs (n=1, n=2, n=3)
4. Check that your base case is correct
5. Verify that each recursive call makes progress toward the base case

Good luck!

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Swift Tuition CP143 Learning Package