C Programming Code Examples

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Program to Find the Length of the String using Recursion

Program to Find the Length of the String using Recursion

This C Program uses recursive function & counts the number of nodes in a linked list. A linked list is an ordered set of data elements, each containing a link to its successor.

    #include <stdio.h>

    #include <stdlib.h>

    struct node

    {

        int a;

        struct node *next;

    };

    void generate(struct node **);

    int length(struct node*);

    void delete(struct node **);

    int main()

    {

        struct node *head = NULL;

        int count;

        generate(&head);

        count = length(head);

        printf("The number of nodes are: %d\n", count);

        delete(&head);

        return 0;

    }

    void generate(struct node **head)

    {

        /* for unknown number of nodes use x = rand() % 20; */

        int x = 10, j;

        struct node *temp;

        for (j = 0; j < x; j++)

        {

            temp = (struct node *)malloc(sizeof(struct node));

            temp->a = j;

            if (*head == NULL)

            {

                *head = temp;

                (*head)->next = NULL;

            }

            else

            {

                temp->next = *head;

                *head = temp;

            }

        }

    }

    int length(struct node *head)

    {

        if (head->next == NULL)

        {

            return 1;

        }

        return (1 + length(head->next));

    }

    void delete(struct node **head)

    {

        struct node *temp;

        while (*head != NULL)

        {

            temp = *head;

            *head = (*head)->next;

            free(temp);

        }

    }