SinglyLinkList 3 -- Insert

Implement:

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

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

node *LinkList;
void display(node *list);
node *insert(node *list, int data);

void main()
{
    LinkList = insert(LinkList, 1);
    display(LinkList);
    LinkList = insert(LinkList, 2);
    display(LinkList);
}

node* create(node *list)
{
    list = (node *)malloc(sizeof(node));
    return list;
}

void display(node *list)
{
    while(list)
    {
        printf("address:%d, data: %d, its next: %d\n", list, list->data, list->next);
        list = list->next;
    }
}

node* insert(node *list, int data)
{
    node* head = list;

    /* If the list is empty*/
    if(list==NULL)
    {
        list = (node *)malloc(sizeof(node));
        list->data = data;
        list->next = NULL;

        head = list;
        return head;
    }
    /* Iterate through the list till we encounter the last node. */
    while(list->next != NULL)
    {
        list = list->next;
    }

    /* Allocate memory for the new node and put data in it */
    list->next = (node *)malloc(sizeof(node));
    list = list->next;
    list->data = data;
    list->next = NULL;

    return head;
}

Procedure Figure:

Output:

gcc SinglyLinkList3.c -lcurses -o SinglyLinkList3
./SinglyLinkList3address:19963920, data: 1, its next: 0
address:19963920, data: 1, its next: 19963952
address:19963952, data: 2, its next: 0

Remark:

1) Because the code "(node *)malloc(sizeof(node));" will return a node with default value, that‘s why there is no Initialize function implemented.

2) Because C Language doesn‘t support the "&" address-of operator in parameters, so we need to restore the head pointer and return it in Insert function.

3) There will be 2 different operations between empty list and non-empty list.