#include <stdio.h>
#include <stdlib.h>
// Node structure
struct Node {
int data;
struct Node* next;
};
// Function to create a new node
struct Node* createNode(int data) {
struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
if (!newNode) {
printf("Memory error\n");
return NULL;
}
newNode->data = data;
newNode->next = NULL;
return newNode;
}
// Function to insert a node at the beginning of the linked list
struct Node* insertAtBeginning(struct Node* head, int data) {
struct Node* newNode = createNode(data);
if (newNode) {
newNode->next = head;
head = newNode;
}
return head;
}
// Function to insert a node at the end of the linked list
struct Node* insertAtEnd(struct Node* head, int data) {
struct Node* newNode = createNode(data);
if (!head) {
return newNode;
}
struct Node* temp = head;
while (temp->next != NULL) {
temp = temp->next;
}
temp->next = newNode;
return head;
}
// Function to insert a node at a specific position in the linked list
struct Node* insertAtPosition(struct Node* head, int data, int position) {
struct Node* newNode = createNode(data);
if (position == 1) {
newNode->next = head;
head = newNode;
} else {
struct Node* temp = head;
for (int i = 1; i < position - 1 && temp != NULL; ++i) {
temp = temp->next;
}
if (temp == NULL) {
printf("Invalid position\n");
free(newNode);
} else {
newNode->next = temp->next;
temp->next = newNode;
}
}
return head;
}
// Function to print the linked list
void printList(struct Node* head) {
struct Node* temp = head;
while (temp != NULL) {
printf("%d ", temp->data);
temp = temp->next;
}
printf("\n");
}
// Main function for testing the linked list insertion
int main() {
struct Node* head = NULL;
int choice, data, position;
do {
printf("1. Insert at the beginning\n");
printf("2. Insert at the end\n");
printf("3. Insert at a specific position\n");
printf("4. Print the list\n");
printf("5. Exit\n");
printf("Enter your choice: ");
scanf("%d", &choice);
switch (choice) {
case 1:
printf("Enter data to insert: ");
scanf("%d", &data);
head = insertAtBeginning(head, data);
break;
case 2:
printf("Enter data to insert: ");
scanf("%d", &data);
head = insertAtEnd(head, data);
break;
case 3:
printf("Enter data to insert: ");
scanf("%d", &data);
printf("Enter position: ");
scanf("%d", &position);
head = insertAtPosition(head, data, position);
break;
case 4:
printf("Linked list: ");
printList(head);
break;
case 5:
// Free memory before exiting
while (head != NULL) {
struct Node* temp = head;
head = head->next;
free(temp);
}
break;
default:
printf("Invalid choice\n");
}
} while (choice != 5);
return 0;
}