C Exercises: Convert a Singly Linked list into a array

Last update on March 19 2025 12:36:59 (UTC/GMT +8 hours)

12. Linked List to Array Variants

Write a C program that converts a singly linked list into an array and returns it.

Sample Solution:

C Code:

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

// Structure for a node in a singly linked list
struct node 
{
    int num;                // Data of the node
    struct node *nextptr;   // Address of the next node
} *stnode;                  // Pointer to the start of the linked list

// Function prototypes
void createNodeList(int n);  
void To_Array(struct node *head, int *array);

int main()
{
    int n;
    printf("\nLinked List: Convert a Singly Linked list into an array:\n");
    printf("-------------------------------------------------------------\n");		
    printf("Input the number of nodes: ");
    scanf("%d", &n);

    // Creating a singly linked list
    createNodeList(n);

    // Converting the linked list to an array
    printf("\nReturn data entered in the list as an array:\n");
    int arr[n];
    To_Array(stnode, arr);

    // Displaying the elements of the array
    for (int i = 0; i < n; i++)
        printf("%d ", arr[i]);

    return 0;
}

// Function to create a singly linked list with 'n' nodes
void createNodeList(int n)
{
    struct node *fnNode, *tmp;
    int num, i;

    // Allocating memory for the first node
    stnode = (struct node *)malloc(sizeof(struct node));

    if(stnode == NULL) // Check if memory allocation failed
    {
        printf(" Memory can not be allocated.");
    }
    else
    {
        // Input data for the first node
        printf(" Input data for node 1 : ");
        scanf("%d", &num);
        stnode->num = num;      
        stnode->nextptr = NULL;  
        tmp = stnode;

        // Creating 'n' nodes and adding to the linked list
        for(i = 2; i <= n; i++)
        {
            fnNode = (struct node *)malloc(sizeof(struct node));
            if(fnNode == NULL)
            {
                printf(" Memory can not be allocated.");
                break;
            }
            else
            {
                // Input data for each node
                printf(" Input data for node %d : ", i);
                scanf(" %d", &num);

                fnNode->num = num;       
                fnNode->nextptr = NULL;  

                tmp->nextptr = fnNode;  
                tmp = tmp->nextptr; 
            }
        }
    }
}

// Function to convert a singly linked list into an array
void To_Array(struct node *head, int *array) {
    struct node *current = head;
    int i = 0;
    // Traverse the linked list and copy elements to the array
    while (current != NULL) {
        array[i] = current->num;
        current = current->nextptr;
        i++;
    }
}

Sample Output:


Linked List: Convert a Singly Linked list into an array:
-------------------------------------------------------------
Input the number of nodes: 4
 Input data for node 1 : 10
 Input data for node 2 : 20
 Input data for node 3 : 30
 Input data for node 4 : 40

Return data entered in the list as an array:
10 20 30 40

Flowchart :

For more Practice: Solve these Related Problems:

Write a C program to convert a singly linked list into a dynamically allocated array.
Write a C program to convert a linked list into an array and then sort the array elements.
Write a C program to convert only the first half of a linked list into an array.
Write a C program to extract nodes that satisfy a given condition (e.g., prime numbers) into an array.

C Programming Code Editor:

Previous: Convert a Singly Linked list into a string.
Next: Combine two sorted singly linked lists.