Recursion:-
The method of calling a function into itself is known as recursion. It increases the execution speed of a compiler but occupies a lot of memory.
Example:-
int factorial (int n)
{
if(n==0)
{
return 1;
}
else
{
return n*factorial(n-1);
}
}
void main()
{
int n,r;
printf("enter any no.");
scanf("%d",&n);
r=factorial(n);
printf("%d",r);
}
Result:-
5!=5*4*3*2*1
=5*4!
formula of factorial:
n!=n*(n-1)!