a) Insert a node in the beginning

b) Insert a node in the end

c) Insert a node after a specific node

d) Deleting a specific node

e) Displaying the list

Mumbai University > COMPS > Sem 3 > Data Structures

Marks: 10 M

Year: May 2014, Dec 2014

#include<stdio.h>
#include<conio.h>
struct node *insert_begin(struct node *start)
{
    struct node *new_node;
    int num;
    printf("\n enter the value");
    scanf("%d",&num);
    new_node=(struct node *)malloc(sizeof(struct node));
    new_node->data=num;
    new_node->next=start;
    start=new_node;
    return start;
}
struct node *insert_end(struct node *start)
{
    struct node *new_node,*ptr;
    ptr=start;
    int num;
    printf("\n enter the value");
    scanf("%d",&num);
    new_node=(struct node *)malloc(sizeof(struct node));
    new_node->data=num;
    while(ptr->next!=NULL)
{
        ptr=ptr->next;  
    }
    ptr->next=new_node;
    new_node->next=NULL;
    return start;
}

struct node *insert_after(struct node* start)
{
    struct node *new_node,*ptr,*pre_ptr;
    int num,value;
    printf("Enter the data:");
    scanf("%d",num);
    printf("enter the value after which data has to be inserted");
    scanf("%d",&value);
    new_node=(struct node *)malloc(sizeof(struct node));
    new_node->data=num;
    ptr=start;
    pre_ptr=ptr;
    while(pre_ptr->data!=val)
    {
        pre_ptr=ptr;
        ptr=ptr->next;
    }
    pre_ptr->next=new_node;
    new_node->next=ptr;
    return start;
}
struct node *delete_node(struct node *start)
{
    struct node *ptr,*pre_ptr;
    int val;
    printf("\n enter value of node which has to be deleted:");
    scanf("%d",&val);
    ptr=start;
    if(ptr->data==val)
    {
        start=start->next;
        free(ptr);
        return start;
    }
    else
    {
        while(ptr->data!=val)
        {
            pre_ptr=ptr;
            ptr=ptr->next;
        }
        pre_ptr->next=ptr->next;
        free(ptr);
        return start;

    }
}
struct node *display_list(struct node *start)
{
    struct node *ptr;
    ptr=start;
    while(ptr!=NULL)
    {
        printf("\t %d|"ptr->data);
        ptr=ptr->next;

    }
    return start;
}

struct node
{
    struct node *next;
    struct node *prev;
    int data;
};
struct node *start=NULL;
int main()
{
    int choice;
    printf("\n 1. create linked list");
    printf("\n 2. add in beginning");
    printf("\n 3. add at end");
    printf("\n 4. delete from beginning");
    printf("\n 5. delete from end");
    scanf("%d",&choice);
    switch(choice)
    {
        case 1: start=create_linked_list(start);
        break;
        case 2: start=insert_begin(start);
        break;
        case 3: start=insert_end(start);
        break;
        case 4: start=delete_begin(start);
        break;
        case 5: start=delete_end(start);
        break;
    }
    return0;
}