C program to remove duplicate nodes from the singly linked list

C program to remove duplicate nodes from the singly linked list

// C program to remove duplicate nodes from

// the singly linked list

#include <stdio.h>

#include <stdlib.h>

//Self-referential structure to create the node.

typedef struct tmp {

    int item;

    struct tmp* next;

} Node;

//structure for creating the linked list.

typedef struct

    {

    Node* head;

    Node* tail;

} List;

//Initialize List

void initList(List* lp)

{

    lp->head = NULL;

    lp->tail = NULL;

//Create node and return the reference of it.

Node* createNode(int item)

{

    Node* nNode;

nNode = (Node*)malloc(sizeof(Node));

    nNode->item = item;

    nNode->next = NULL;

    return nNode;

}

//Add a new item at the end of the list.

void addAtTail(List* lp, int item)

{

    Node* node;

    node = createNode(item);

    //if list is empty.

    if (lp->head == NULL) {

        lp->head = node;

        lp->tail = node;

    }

    else {

        lp->tail->next = node;

        lp->tail = lp->tail->next;

    }

}

//Add a new item at beginning of the list.

void addAtHead(List* lp, int item)

{

    Node* node;

    node = createNode(item);

    //if list is empty.

    if (lp->head == NULL) {

        lp->head = node;

        lp->tail = node;

    }

    else {

        node->next = lp->head;

        lp->head = node;

    }

}

//To print the list from start to end of the list.

void printList(List* lp)

{

    Node* node;

    if (lp->head == NULL) {

        printf("\nEmpty List");

        return;

    }

  node = lp->head;

    while (node != NULL) {

        printf("| %05d |", node->item);

        node = node->next;

        if (node != NULL)

            printf("--->");

    }

    printf("\n\n");

}

void dupDelete(List* lp)

{

    Node* current = lp->head;

    Node* index;

    Node* temp;

    while (current != NULL) {

        temp = current;

        index = current->next;

        while (index != NULL) {

            if (current->item == index->item)

                temp->next = index->next;

            else

                temp = index;

            index = index->next;

        }

        current = current->next;

    }

}

//Main function to execute program.

int main()

{

    List* lp;

    lp = (List*)malloc(sizeof(List));

    initList(lp);

    addAtTail(lp, 101);

    addAtTail(lp, 102);

    addAtTail(lp, 101);

    addAtTail(lp, 102);

    addAtTail(lp, 105);

    printf("List:\n");

    printList(lp);

    dupDelete(lp);

    printf("Updated List:\n");

    printList(lp);

    return 0;

}