Answers for "linked list example in c"

linked list menu driven program in c

#include<stdio.h>
#include<conio.h>
#include<process.h>
 
struct node
{
    int data;
    struct node *next;
}*start=NULL,*q,*t;
 
int main()
{
    int ch;
    void insert_beg();
    void insert_end();
    int insert_pos();
    void display();
    void delete_beg();
    void delete_end();
    int delete_pos();
 
    while(1)
    {
        printf("nn---- Singly Linked List(SLL) Menu ----");
        printf("n1.Insertn2.Displayn3.Deleten4.Exitnn");
        printf("Enter your choice(1-4):");
        scanf("%d",&ch);
 
        switch(ch)
        {
            case 1:
                    printf("n---- Insert Menu ----");
                    printf("n1.Insert at beginningn2.Insert at endn3.Insert at specified positionn4.Exit");
                    printf("nnEnter your choice(1-4):");
                    scanf("%d",&ch);
 
                    switch(ch)
                    {
                        case 1: insert_beg();
                                break;
                        case 2: insert_end();
                                break;
                        case 3: insert_pos();
                                break;
                        case 4: exit(0);
                        default: printf("Wrong Choice!!");
                    }
                    break;
 
            case 2: display();
                    break;
 
            case 3: printf("n---- Delete Menu ----");
                    printf("n1.Delete from beginningn2.Delete from endn3.Delete from specified positionn4.Exit");
                    printf("nnEnter your choice(1-4):");
                    scanf("%d",&ch);
 
                    switch(ch)
                    {
                        case 1: delete_beg();
                                break;
                        case 2: delete_end();
                                break;
                        case 3: delete_pos();
                                break;
                        case 4: exit(0);
                        default: printf("Wrong Choice!!");
                    }
                    break;
            case 4: exit(0);
                    default: printf("Wrong Choice!!");
        }
    }
    return 0;
}
 
void insert_beg()
{
    int num;
    t=(struct node*)malloc(sizeof(struct node));
    printf("Enter data:");
    scanf("%d",&num);
    t->data=num;
 
    if(start==NULL)        //If list is empty
    {
        t->next=NULL;
        start=t;
    }
    else
    {
        t->next=start;
        start=t;
    }
}
 
void insert_end()
{
    int num;
    t=(struct node*)malloc(sizeof(struct node));
    printf("Enter data:");
    scanf("%d",&num);
    t->data=num;
    t->next=NULL;
 
    if(start==NULL)        //If list is empty
    {
        start=t;
    }
    else
    {
        q=start;
        while(q->next!=NULL)
        q=q->next;
        q->next=t;
    }
}
 
int insert_pos()
{
    int pos,i,num;
    if(start==NULL)
    {
        printf("List is empty!!");
        return 0;
    }
 
    t=(struct node*)malloc(sizeof(struct node));
    printf("Enter data:");
    scanf("%d",&num);
    printf("Enter position to insert:");
    scanf("%d",&pos);
    t->data=num;
 
    q=start;
    for(i=1;i<pos-1;i++)
    {
        if(q->next==NULL)
        {
            printf("There are less elements!!");
            return 0;
        }
 
        q=q->next;
    }
 
    t->next=q->next;
    q->next=t;
    return 0;
}
 
void display()
{
    if(start==NULL)
    {
        printf("List is empty!!");
    }
    else
    {
        q=start;
        printf("The linked list is:n");
        while(q!=NULL)
        {
            printf("%d->",q->data);
            q=q->next;
        }
    }
}
 
void delete_beg()
{
    if(start==NULL)
    {
        printf("The list is empty!!");
    }
    else
    {
        q=start;
        start=start->next;
        printf("Deleted element is %d",q->data);
        free(q);
    }
}
 
void delete_end()
{
    if(start==NULL)
    {
        printf("The list is empty!!");
    }
    else
    {
        q=start;
        while(q->next->next!=NULL)
        q=q->next;
 
        t=q->next;
        q->next=NULL;
        printf("Deleted element is %d",t->data);
        free(t);
    }
}
 
int delete_pos()
{
    int pos,i;
 
    if(start==NULL)
    {
        printf("List is empty!!");
        return 0;
    }
 
    printf("Enter position to delete:");
    scanf("%d",&pos);
 
    q=start;
    for(i=1;i<pos-1;i++)
    {
        if(q->next==NULL)
        {
            printf("There are less elements!!");
            return 0;
        }
        q=q->next;
    }
 
    t=q->next;
    q->next=t->next;
    printf("Deleted element is %d",t->data);
    free(t);
 
    return 0;
}

how to make a linked list in c

typedef struct node{
    int value; //this is the value the node stores
    struct node *next; //this is the node the current node points to. this is how the nodes link
}node;

node *createNode(int val){
    node *newNode = malloc(sizeof(node));
    newNode->value = val;
    newNode->next = NULL;
    return newNode;
}

How to create linked lists in C

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

// Represents a node
typedef struct node
{
    int number;
    struct node *next;
}
node;

int main(void)
{
    // List of size 0. We initialize the value to NULL explicitly, so there's
    // no garbage value for our list variable
    node *list = NULL;

    // Allocate memory for a node, n
    node *n = malloc(sizeof(node));
    if (n == NULL)
    {
        return 1;
    }

    // Set the value and pointer in our node
    n->number = 1;
    n->next = NULL;

    // Add node n by pointing list to it, since we only have one node so far
    list = n;

    // Allocate memory for another node, and we can reuse our variable n to
    // point to it, since list points to the first node already
    n = malloc(sizeof(node));
    if (n == NULL)
    {
        free(list);
        return 1;
    }

    // Set the values in our new node
    n->number = 2;
    n->next = NULL;

    // Update the pointer in our first node to point to the second node
    list->next = n;

    // Allocate memory for a third node
    n = malloc(sizeof(node));
    if (n == NULL)
    {
        // Free both of our other nodes
        free(list->next);
        free(list);
        return 1;
    }
    n->number = 3;
    n->next = NULL;

    // Follow the next pointer of the list to the second node, and update
    // the next pointer there to point to n
    list->next->next = n;

    // Print list using a loop, by using a temporary variable, tmp, to point
    // to list, the first node. Then, every time we go over the loop, we use
    // tmp = tmp->next to update our temporary pointer to the next node. We
    // keep going as long as tmp points to somewhere, stopping when we get to
    // the last node and tmp->next is null.
    for (node *tmp = list; tmp != NULL; tmp = tmp->next)
    {
        printf("%in", tmp->number);
    }

    // Free list, by using a while loop and a temporary variable to point
    // to the next node before freeing the current one
    while (list != NULL)
    {
        // We point to the next node first
        node *tmp = list->next;
        // Then, we can free the first node
        free(list);
        // Now we can set the list to point to the next node
        list = tmp;
        // If list is null, when there are no nodes left, our while loop will stop
    }
}