Recursion-in-cpp-

C++ Recursion and String Reversal Programs

This repository contains two simple C++ programs that demonstrate recursion and string manipulation.

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What is Recursion?

Recursion is a programming technique where a function calls itself to solve a smaller instance of the same problem. It is commonly used for problems that can be broken down into repetitive, smaller subproblems, such as factorial, summation, and Fibonacci sequences. The key components of recursion are:

• Base Case: The condition where the recursion stops.
• Recursive Case: The part where the function calls itself.

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Programs Overview

File	Objective	Description
sum.cpp	Summation using Recursion	Calculates the sum of numbers from 1 to n using a recursive function. Demonstrates breaking the problem into smaller subproblems until the base case is reached.
reverse.cpp	String Reversal	Reverses a given string without using built-in reverse functions. Uses a loop to traverse the string from end to start and constructs the reversed string.

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Algorithms

1. sum.cpp – Summation using Recursion

• Step 1: Define function sum(n)
  • If n <= 1, return 1 (base case)
  • Else return n + sum(n-1) (recursive case)
• Step 2: In main(), take input n from user
• Step 3: Call sum(n) and print result

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2. reverse.cpp – String Reversal

• Step 1: Define function reves(string n)
  • Initialize an empty string st1
  • Loop from end of n to start, appending each character to st1
  • Return st1
• Step 2: In main(), take input string n from user
• Step 3: Call reves(n) and print the reversed string

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Concepts Demonstrated

• Recursion in C++ (sum.cpp)
• String manipulation using loops (reverse.cpp)
• Basic input/output using cin and cout