Find the length of a linked list without using recursion

In this tutorial, we will learn how to find a linked list length without using recursion with the help of the C program? By Piyas Mukherjee Last updated : August 02, 2023

Input

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

Output

The no of nodes in the list, c

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.

Pseudo Code

Begin
    temp=head
    c=0 //counter to store count of nodes
    while(temp!=NULL) //upto end of linked list
        begin
        c=c+1
        temp=temp->next
    End while
End

C program to find the length of a linked list without using recursion

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

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

int length(node* temp);

//function to find length iteratively
int length(node* temp)
{
    int c = 0;
    //travarsing to the end of the list and 
    //count the number of nodes
    while (temp != NULL) {
        c = c + 1;
        temp = temp->next;
    }
    return c;
}

// Main code
int main()
{
    node *head = NULL, *temp, *temp1;
    int choice, count;
    //building linked list
    do {
        temp = (node*)malloc(sizeof(node));
        if (temp != NULL) {
            printf("\nEnter the element in the list : ");
            scanf("%d", &temp->data);
            temp->next = NULL;
            if (head == NULL) {
                head = temp;
            }
            else {
                temp1 = head;
                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 more data on the list enter 1 : ");
        scanf("%d", &choice);
    } while (choice == 1);

    //Now counting the length of the list 
    //using a user defined function
    count = length(head);
    printf("\nThe length of the list is : %d", count);

    return 0;
}

Output

Enter the element in the list : 1

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

Enter the element in the list : 2

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

Enter the element in the list : 3

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

Enter the element in the list : 4

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

Enter the element in the list : 5

If you wish to add more data on the list enter 1 : 0

The length of the list is : 5