Question

Please explain step by step what is going on each step.please clearly explain line by line the working of code . Also provide the output. I would rate positively.

Thank you so much .

#include <stdio.h>

#include <stdlib.h>

struct  node  {

      int data;

      struct  node  *next;  

};  

struct  node  *head = NULL;

void  printList() {

      struct  node  *ptr  = head;

      printf("\nhead:");  

  

      while(ptr !=  NULL) {

            printf("node  addr:%p   \tdata:%d   \tnext addr:%p\n”, ptr,ptr->data,ptr->next);

              

            ptr = ptr->next;  

      }

      printf("  [null]\n");

}

void  insert(int  data) {

      struct  node  *link = (struct node*)        malloc(sizeof(struct  node));

      link->data  = data;

      link->next  = head;

      head  = link;

}

int main()  {

      insert(15);

      insert(2);  

      insert(33);

      insert(5);  

      insert(75);

      insert(13);

      printList();  

      return  0;  

}

Answer 1

OUTPUT:

head:node addr:0x1bec0b0    data:13    next addr:0x1bec090
node addr:0x1bec090    data:75    next addr:0x1bec070
node addr:0x1bec070    data:5    next addr:0x1bec050
node addr:0x1bec050    data:33    next addr:0x1bec030
node addr:0x1bec030    data:2    next addr:0x1bec010
node addr:0x1bec010    data:15    next addr:(nil)
[null]

The line by line explanation of the source code is given below with comments:

//header file
#include <stdio.h>
#include <stdlib.h>

//structure declaration
struct node {
//structure member list
int data;
struct node *next;
};

//declare a structure type variable and initialize with NULL value
//'head' is the base pointer of the linked list
struct node *head = NULL;

//function to print the node value with address
void printList() {
//declare a structure type variable and initialize with head
struct node *ptr = head;
  
//display the message on the computer screen
printf("\nhead:");
  
//display the node value and address until the end of the linked list or NULL pointer
//The last node of the linked list is assigned with a NULL pointer
//if we found the address value in any node equal to NULL then it is the last node
while(ptr != NULL) {
  
//display the node address, value stored in node and the address of the next node
printf("node addr:%p \tdata:%d \tnext addr:%p\n", ptr,ptr->data,ptr->next);
  
//assign the pointer to the next node
ptr = ptr->next;
}
//display the message on the computer screen
printf(" [null]\n");

}

//function to insert a new node at the front of the linked list
void insert(int data) {

//create a new node and allocate memory by using the malloc() function
struct node *link = (struct node*) malloc(sizeof(struct node));
  
//assign the new node data field with the paramener value
link->data = data;
  
//assign the new node address field with the head pointer
link->next = head;
  
//assign the head node to the new node
head = link;

}

int main() {

//insert 15 to the linked list
insert(15);
  
//insert 2 to the linked list
insert(2);
  
//insert 33 to the linked list
insert(33);
  
//insert 5 to the linked list
insert(5);
  
//insert 75 to the linked list
insert(75);
  
//insert 13 to the linked list
insert(13);
  
//display the linked list by calling printList() function
printList();

return 0;

}