Recursive Function
In C programming, recursion is a technique where a function calls itself to
solve a problem.
Any function which calls itself is called recursive function, and such function
calls are called recursive calls.
However, it is important to impose a termination condition of recursion.
Recursion code is shorter than iterative code.
A recursive function performs the tasks by dividing it into the subtasks.
There is a termination condition defined in the function which is satisfied
by some specific subtask. After this, the recursion stops and the final result
is returned from the function.
Factorial of a Number using Recursion
#include <stdio.h>
int factorial(int); return 0;
int main() { }
int num; int factorial(int n) {
printf("Enter a positive integer: "); if (n == 0 || n == 1) {
scanf("%d", &num); return 1;
} else {
if (num < 0) { // Recursive call to calculate factorial
printf("Factorial is not defined for for n-1 and multiply it with n
negative numbers.\n"); return n * factorial(n - 1);
} else { }
int result = factorial(num); }
printf("Factorial of %d is %d.\n", num,
result);
}
Example of Fibonacci series using recursion
#include <stdio.h> }
int fibonacci(int); printf("\n");
}
int main() {
int n; return 0;
printf("Enter the value of n: "); }
scanf("%d", &n); int fibonacci(int n) {
if (n == 0) {
if (n < 0) { return 0;
printf("Invalid input! n must be a non- } else if (n == 1) {
negative integer.\n"); return 1;
} else { } else {
printf("Fibonacci series up to the %dth return fibonacci(n - 1) + fibonacci(n - 2);
term:\n", n);
for (int i = 0; i < n; i++) { }
printf("%d ", fibonacci(i)); }
