C program to traverse the linked list

In this tutorial, we will learn how to traverse the linked list using the C program? Submitted by Nidhi, on August 19, 2021

Problem statement

Create a linked list, traverse, and print the linked list.

C program to traverse the linked list

The source code to traverse the linked list is given below. The given program is compiled and executed using GCC compile on UBUNTU 18.04 OS successfully.

// C program to traverse the linked list

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

//Self-referential structure to create node.
typedef struct tmp {
    int item;
    struct tmp* next;
} Node;

//structure for create 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 reference of it.
Node* createNode(int item)
{
    Node* nNode;

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

    nNode->item = item;
    nNode->next = NULL;

    return nNode;
}

//Add new item at the end of 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 new item at begning 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 list from start to end of the list.
void TraverseList(List* lp)
{
    Node* node;

    if (lp->head == NULL) {
        printf("\nEmpty List");
        return;
    }

    node = lp->head;

    printf("List:\n");
    while (node != NULL) {
        printf("| %05d |", node->item);
        node = node->next;

        if (node != NULL)
            printf("--->");
    }
    printf("\n\n");
}

//Main function to execute program.
int main()
{
    List* lp;

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

    initList(lp);

    addAtTail(lp, 100);
    addAtTail(lp, 200);
    addAtHead(lp, 300);
    addAtHead(lp, 400);
    addAtHead(lp, 500);

    TraverseList(lp);

    return 0;
}

Output

List:
| 00500 |--->| 00400 |--->| 00300 |--->| 00100 |--->| 00200 |

Explanation

Here, we created a self-referential structure to implement a linked list, a function to add a node at the start and end of the list, a function TraverseList() to traverse, and print linked list items.

In the main() function, we created the linked list and traversed the linked list items, and printed them on the console screen.