# Find the length of a linked list using recursion

In this article, we are going to see how to write a recursive function to find the length of a linked list using C program?
Submitted by Piyas Mukherjee, on January 24, 2019

Solution:

Recursive function: func_length(node *temp)

Input:

A singly linked list whose address of the first node is stored in a pointer, say head.

Output:

Data structure used:

Singly linked list where each node contains a data element say data, and the address of the immediate next node say next, with head holding the address of the first node.

Steps:

Declare a global variable l=0

Pseudo code:

```Begin
If(temp=NULL)
print l //printing final length
Else
l=l+1;
length(temp->next); //recursive call
End If-else
End
```

C code:

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

typedef struct list
{
int data;
struct list *next;
}node;

//global variable to store length
int l=0;

int main()
{
int len,choice,count=0,key;
do
{
temp=(node *)malloc(sizeof(node));
if(temp!=NULL)
{
printf("\nEnter the element in the list : ");
scanf("%d",&temp->data);
temp->next=NULL;
{
}
else
{
while(temp1->next!=NULL)
{
temp1=temp1->next;
}
temp1->next=temp;
}
}
else
{
printf("\nMemory not avilable...node allocation is not possible");
}
printf("\nIf you wish to add m ore data on the list enter 1 : ");
scanf("%d",&choice);
}while(choice==1);

printf("The list has a total of %d no of nodes",l);

return 0;
}

//recursive function to find length
int length(node *temp)
{
if(temp==NULL)
return l;
else
{
l=l+1;
length(temp->next);
}
}
```

Output

```Enter the element in the list : 1

If you wish to add m ore data on the list enter 1 : 1

Enter the element in the list : 2

If you wish to add m ore data on the list enter 1 : 1

Enter the element in the list : 3

If you wish to add m ore data on the list enter 1 : 1

Enter the element in the list : 4

If you wish to add m ore data on the list enter 1 : 1

Enter the element in the list : 5

If you wish to add m ore data on the list enter 1 : 1

Enter the element in the list : 6

If you wish to add m ore data on the list enter 1 : 0
The list has atotal of 6 no of nodes
```

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