Deletion_By_Position.c

// A complete working C program to delete a node in a linked list 
// at a given position 
#include <stdio.h> 
#include <stdlib.h> 
  
// A linked list node 
struct Node 
{ 
    int data; 
    struct Node *next; 
}; 
  
/* Given a reference (pointer to pointer) to the head of a list 
   and an int, inserts a new node on the front of the list. */
void push(struct Node** head_ref, int new_data) 
{ 
    struct Node* new_node = (struct Node*) malloc(sizeof(struct Node)); 
    new_node->data  = new_data; 
    new_node->next = (*head_ref); 
    (*head_ref)    = new_node; 
} 
  
/* Given a reference (pointer to pointer) to the head of a list 
   and a position, deletes the node at the given position */
void deleteNode(struct Node **head_ref, int position) 
{ 
   // If linked list is empty 
   if (*head_ref == NULL) 
      return; 
  
   // Store head node 
   struct Node* temp = *head_ref; 
  
    // If head needs to be removed 
    if (position == 0) 
    { 
        *head_ref = temp->next;   // Change head 
        free(temp);               // free old head 
        return; 
    } 
  
    // Find previous node of the node to be deleted 
    for (int i=0; temp!=NULL && i<position-1; i++) 
         temp = temp->next; 
  
    // If position is more than number of ndoes 
    if (temp == NULL || temp->next == NULL) 
         return; 
  
    // Node temp->next is the node to be deleted 
    // Store pointer to the next of node to be deleted 
    struct Node *next = temp->next->next; 
  
    // Unlink the node from linked list 
    free(temp->next);  // Free memory 
  
    temp->next = next;  // Unlink the deleted node from list 
} 
  
// This function prints contents of linked list starting from 
// the given node 
void printList(struct Node *node) 
{ 
    while (node != NULL) 
    { 
        printf(" %d ", node->data); 
        node = node->next; 
    } 
} 
  
/* Drier program to test above functions*/
int main() 
{ 
    /* Start with the empty list */
    struct Node* head = NULL; 
  
    push(&head, 7); 
    push(&head, 1); 
    push(&head, 3); 
    push(&head, 2); 
    push(&head, 8); 
  
    puts("Created Linked List: "); 
    printList(head); 
    deleteNode(&head, 4); 
    puts("\nLinked List after Deletion at position 4: "); 
    printList(head); 
    return 0; 
}