Recursion in C

Recursion means that a function calls itself again. It is a powerful method used to solve complex problems. Recursion is very helpful for breaking down many problems into smaller sub-problems. To solve such problems, we use Recursive Functions. In the C language, a recursive function calls itself until some base condition is met.

Base Case: This is the condition where the recursion ends. The base case is very important because, without it, the recursion would become infinite, and the program could crash.

Recursive Case: This is the part where the function calls itself again, but each time the problem gets a little smaller.

Direct Recursion: A function calls itself directly.

Indirect Recursion: A function calls another function, and that second function then calls the first function back.

The document provides and explains recursive C programs for calculating the factorial of a number and for generating the Fibonacci series, highlighting the base and recursive cases for each.

Advantages: The code is simpler and clearer for certain problems (like tree traversal), and it makes solving complex problems easier by breaking them down.

Disadvantages: Risk of stack overflow if recursion is too deep or infinite, and potentially higher time and space complexity due to the overhead of function calls.

Recursion involves a function calling itself repeatedly and breaking the problem into smaller pieces. Iteration uses a loop (like `for` or `while`) to solve a problem. A comparison table highlights the differences.