Recursion in C programming language

Recursion in C programming language

In this tutorial, we will discuss recursion in C programming language

A function calling itself during its execution. it is called a recursive function. another word, a function calling from the definition of the same function is known as a recursion

 

Example of recursive function

 

The flow of control of recursive function

 

Find factorial using the recursive function

#include <stdio.h>
#include <stdlib.h>

int find_Factorial(int n);//declare a function to find the factorial.
int main()
{
    int num;
    printf("Enter the number to find factorial: ");
    scanf("%d",&num);
    printf("Factorial of %d=%d", num, find_Factorial(num));//call the function inside the main() function
    getch();
    return 0;
}

//user defined function
int find_Factorial(int num) //define the function according to declaration
{
    if(num<1)
        return 1;
    else
        return num*find_Factorial(num-1);//find_Factorial function calls itself
}

When the above code is executed, it produces the following results

Enter the number to find factorial: 5
Factorial of 6 = 120

In the above program, first, find_Factorial() function called inside the main () function with passing its argument.

when the value passed to the function, it is stored in the num variable.

Initially, the value of num is 5 to pass as an argument, then the function calls itself, in it the value of num reduce by 1 and it becomes 4 and it passes to beginning “find_Factorial()” function. it continuously reduces by one in every stage until it comes to 0.

when the num becomes less then 1, here, the if condition returns false and flow of control moves to else part for execution.

else part is executed and excludes from the function

 

Explanation of recursive function to find factorial

 

Advantages of recursion in C

Easy to understand and the code becomes readable and reduces the number of lines of the program.

This recursion  is used  to make a complex task easy and also  flexible and repeatedly functioning is easier with using nesting iteration

Disadvantages of recursion in C

Tracing and debugging are very difficult

Every recursive lacks a separate memory location, as extra memory is required process becomes very slow

 

the same program like this

Python recursion

 

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