C Programming - SPLessons
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Recursion in C

Recursion in C

shape Description

Recursion in C can be defined as the process of calling a function itself repeatedly. The function is called as "Recursive function". This is similar to looping concept which repeats the same code discussed earlier. Recursion in C helps in expressing ideas in which the recursive call result, necessary to complete the task. Sometimes the process may complete without the recursive call also.

shape Syntax

void recursive_function() { //statements; recursive_function(); } int main() { //statements; recursive_function(); }

shape Conceptual figure

What happens if Recursion in C continues for many times..?

shape Reason

Basic function of Recursion in C is to repeat many times and it may happen forever.But, in real time what happens is,after some recursions, the program gets crashed. This is because,

shape Example - 1

Control flow for factorial example will be as follows. [c] //program for finding factorial of a number #include<stdio.h> #include<conio.h> #include<math.h> int fact(int); int main() { int number,f; printf("\nEnter a number: "); scanf("%d",&number); f=fact(number); printf("\nFactorial of %d is: %d",number,f); return 0; } int fact(int n) { if(n==1) { return 1; } else return(n*fact(n-1)); }[/c] Output: [c] Enter a number: 5 Factorial of 5 is: 120 [/c]

shape Example - 2

[c] //program for finding sum of n numbers #include<stdio.h> #include<math.h> int main() { int a,sum; printf("Enter the value of n: "); scanf("%d",&a); sum = getSum(a); printf("Sum of n numbers: %d",sum); return 0; } int getSum(a) { static int sum=0; if(a>0) { sum = sum + a; getSum(a-1); } return sum; } [/c] Output: [c] Enter the value of n: 8 Sum of n numbers: 36 [/c]

shape Advantages

shape Disadvantage


shape Key Points

  • Recursive function calls itself for multiple times.
  • Stacks are created during recursion.

shape Programming Tips

Take care of count of Recursion in C because it leads to overflow.