C Tutorials
| Recursion in C |
Recursion is the process of repeating items in a self-similar way. Same applies in programming languages as well where if a programming allows you to call a function inside the same function that is called recursive call of the function as follows.
void recursion()
{
recursion(); /* function calls itself */
}
int main()
{
recursion();
}
The C programming language supports recursion ie. a function to call itself. But while using recursion, programmers need to be careful to define an exit condition from the function, otherwise it will go in infinite loop.
Recursive function are very useful to solve many mathematical problems like to calculate factorial of a number, generating fibonacci series etc.
| Factorial |
Following is an example which calculate factorial for a given number using a recursive function:
#include <stdio.h>
int factorial(unsigned int i)
{
if(i <= 1)
{
return 1;
}
return i * factorial(i - 1);
}
int main()
{
int i = 15;
printf("Factorial of %d is %d\n", i, factorial(i));
return 0;
}
| Fibonacci Series |
Following is another example which generates fibonacci series for a given number using a recursive function:
#include <stdio.h>
int fibonaci(int i)
{
if(i == 0)
{
return 0;
}
if(i == 1)
{
return 1;
}
return fibonaci(i-1) + fibonaci(i-2);
}
int main()
{
int i;
for (i = 0; i < 10; i++)
{
printf("%d\t%n", fibonaci(i));
}
return 0;
}
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