Please write in c++ showing comments of what is being done. Thank you. Existing code is pasted below question.

Existing code to change:

#include

//set basic structure for node

struct node {

int data;

int key;

struct node* next;

};

//set where both sides start on NULL

struct node* head = NULL;

struct node* current = NULL;

//void tp display the list

void printList() {

struct node* printList = head;

printf(" [ ");

//telling function to start from the beginning

while (printList != NULL) {

printf("(%d,%d) ", printList->key, printList->data);

printList = printList->next;

}

printf(" ]");

}

//inserting link at the first location

void insertFirst(int key, int data) {

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

//types of links

link->key = key;

link->data = data;

//point it to old first node

link->next = head;

//point first to new first node

head = link;

}

//function to delete the first item in the list

struct node* deleteFirst() {

//save reference to first link

struct node* tempLink = head;

head = head->next;

//return the deleted link

return tempLink;

}

//to find if the list is empty

bool isEmpty() {

return head == NULL;

}

//to find the length of the current link

int length() {

int length = 0;

struct node* current;

for (current = head; current != NULL; current = current->next) {

length++;

}

return length;

}

//find a link with given key

struct node* find(int key) {

//start from the first link

struct node* current = head;

//if list is empty

if (head == NULL) {

return NULL;

}

while (current->key != key) {

//if it is last node

if (current->next == NULL) {

return NULL;

}

else {

current = current->next;

}

}

//if data found, return the current Link

return current;

}

//delete a link with given key *DELETE IS NOT WORKING EVEN THOUGH IT IS DESIGNATED TO A POINTER*

struct node* delete(int key) {

//start from the first link

struct node* current = head;

struct node* previous = NULL;

//if list is empty

if (head == NULL) {

return NULL;

}

/avigate through list

while (current->key != key) {

//if it is last node

if (current->next == NULL) {

return NULL;

}

else {

//store reference to current link

previous = current;

//move to next link

current = current->next;

}

}

if (current == head) {

//change first link to point to next link

head = head->next;

}

else {

previous->next = current->next;

}

return current;

}

void sort() {

int i, j, k, tempKey, tempData;

struct node* current;

struct node* next;

int size = length();

k = size;

for (i = 0; i

current = head;

next = head->next;

for (j = 1; j

if (current->data > next->data) {

tempData = current->data;

current->data = next->data;

next->data = tempData;

tempKey = current->key;

current->key = next->key;

next->key = tempKey;

}

current = current->next;

next = next->next;

}

}

}

// reverse the order

void reverse(struct node** head_ref) {

struct node* prev = NULL;

struct node* current = *head_ref;

struct node* next;

while (current != NULL) {

next = current->next;

current->next = prev;

prev = current;

current = next;

}

*head_ref = prev;

}

int main() {

insertFirst(1, 10);

insertFirst(2, 20);

insertFirst(3, 30);

insertFirst(4, 1);

insertFirst(5, 40);

insertFirst(6, 56);

printf("Original List: ");

//print list

printList();

while (!isEmpty()) {

struct node* temp = deleteFirst();

printf(" Deleted value:");

printf("(%d,%d) ", temp->key, temp->data);

}

printf(" List after deleting all items: ");

printList();

insertFirst(1, 10);

insertFirst(2, 20);

insertFirst(3, 30);

insertFirst(4, 1);

insertFirst(5, 40);

insertFirst(6, 56);

printf(" Restored List: ");

printList();

printf(" ");

struct node* foundLink = find(4);

if (foundLink != NULL) {

printf("Element found: ");

printf("(%d,%d) ", foundLink->key, foundLink->data);

printf(" ");

}

else {

printf("Element not found.");

}

//delete the fourth element

delete(4); // *AGAIN DELETE WILL NOT WORK, I WANTED TO DELETE THE FOURTH ELEMENT, BUT WILL ONLY ALLOW DELETION OF "POINTERS" *

printf("List after deleting an item: ");

printList();

printf(" ");

foundLink = find(4);

if (foundLink != NULL) {

printf("Element found: ");

printf("(%d,%d) ", foundLink->key, foundLink->data);

printf(" ");

}

else {

printf("Element not found.");

}

//data to print at the end of the file

printf(" ");

sort();

printf("List after sorting the data: ");

printList();

reverse(&head);

printf(" List after reversing the data: ");

printList();

}

This is what I was asked to do, and what the existing code was doing. These are the steps that were given for the existing code listed above:

1. Create 10 random numbers of value 100-150 as elements of a doubly linked list and circular linked list. Perform the following tasks (write functions and calling them in main())
2. Create both lists by insert begin and print each of them.
3. Insert 1000 at the beginning of the circular list and print. Draw a picture as how will perform the task. Print the list.
4. Insert 3000 at the 5^th position of the doubly linked list. Draw a picture to show how insertion happened. Print the list.
5. Delete 4^th element from the circular list. Draw a picture to show how deletion happened. Print the list.
6. Convert the doubly linked list to a doubly linked circular list. How will you confirm this list is circular?
7. Create a sorted doubly linked list by inserting the generated random numbers one by one in an ascending order.

1. a) Create 100 random numbers of value 100-150 as elements in a txt file b) Read values from the file to create a class of singular linked list in sorted order and print forward and backward of the list. Create a member function to insert 1000 in the 41 element of the list. Print the final list using an iterator class. c) Read values from the file to create a template class of doubly linked list and print forward and backward the list. Create a member function to delete all the elements in the range 120-130. Print the shortened list using an iterator class. d) Read values from the file to create a class of circular linked list and print forward and backward the list. Search element 135 using a member function and if present replace it (and duplicates) with 150. Print the final list using an iterator class e) Code to create a linked list say having 5 nodes using static allocation. Please write in C++ and use comments explaining steps being done. // Weekly_Task2.cpp: This file contains the 'main' function. Program execution begins and ends there. #include //set basic structure for node struct node { int data; int key; struct node* next; }; //set where both sides start on NULL struct node* head = NULL; struct node* current = NULL; //void tp display the list void printList() { struct node* printList = head; printf(" [ "); //telling function to start from the beginning while (printList != NULL) { printf("%d, %d) ", printList->key, printList->data); printList = printList->next; } printf("]"); } //inserting link at the first location void insertFirst(int key, int data) { struct node* link = (struct node*)malloc(sizeof(struct node)); //types of links link->key = key; link->data = data; //point it to old first node link->next = head; //point first to new first node head = link; } //function to delete the first item in the list struct node* deleteFirst() { //save reference to first link struct node* tempLink = head; head = head->next; //return the deleted link return tempLink; } //to find if the list is empty bool isEmpty() { return head == NULL; } //to find the length of the current link int length() { int length = 0; struct node* current; for (current = head; current != NULL; current = current->next) { length++; } return length; } //find a link with given key struct node* find(int key) { //start from the first link struct node* current = head; //if list is empty if (head == NULL) { return NULL; } while (current->key != key) { //if it is last node if (current->next == NULL) { return NULL; else { current = current->next; } } //if data found, return the current Link return current; } *DELETE IS NOT WORKING EVEN THOUGH IT IS 1/delete a link with given key DESIGNATED TO A POINTER* struct node* delete(int key) { //start from the first link struct node* current = head; struct node* previous = NULL; //if list is empty if (head == NULL) { return NULL; } 1avigate through list while (current->key != key) { //if it is last node if (current->next == NULL) { return NULL; } else { //store reference to current link previous = current; //move to next link current = current->next; } } == if (current head) { //change first link to point to next link head = head->next; } else { previous->next = current->next; } return current; } void sort() { int i, j, k, tempkey, tempData; struct node* current; struct node* next; int size = length(); k = size; for (i = 0; i next; for (j = 1; j data > next->data) { tempData = current->data; current->data = next->data; next->data = tempData; tempkey = current->key; current ->key = next ->key; next->key = tempkey; } current = current->next; next = next->next; } } } // reverse the order void reverse(struct node** head_ref) { struct node* prev = NULL; struct node* current = *head_ref; struct node* next; while (current != NULL) { next = current->next; current->next = prev; prev = current; current = next; } *head_ref = prev; } int main() { insertFirst(1, 10); insert First(2, 20); insertFirst(3, 30); insert First(4, 1); insertFirst(5, 40); insertFirst(6, 56); printf("Original List: "); //print list printList(); while (!isEmpty()) { struct node* temp = deleteFirst(); printf(" Deleted value:"); printf("%d,%d) ", temp->key, temp->data); } printf(" List after deleting all items: "); printList(); insert First(1, 10); insert First(2, 20); insert First(3, 30); insert First(4, 1); insert First(5, 40); insertFirst(6, 56); printf(" Restored List: "); printList(); printf(" "); struct node* foundLink = find(4); if (foundLink != NULL) { printf("Element found: "); printf("%d,%d) ", foundLink ->key, foundLink->data); printf(" "); } else { printf("Element not found."); } //delete the fourth element delete(4); // *AGAIN DELETE WILL NOT WORK, I WANTED TO DELETE THE FOURTH ELEMENT, BUT WILL ONLY ALLOW DELETION OF "POINTERS" * printf("List after deleting an item: "); printList(); printf(" "); foundLink = find(4); if (foundLink != NULL) { printf("Element found: "); printf("%d, %d ", foundLink->key, foundLink->data); printf(" "); } else { printf("Element not found."); } //data to print at the end of the file printf(" "); sort(); printf("List after sorting the data: "); printList(); reverse(&head); printf(" List after reversing the data: "); printList(); } 1. a) Create 100 random numbers of value 100-150 as elements in a txt file b) Read values from the file to create a class of singular linked list in sorted order and print forward and backward of the list. Create a member function to insert 1000 in the 41 element of the list. Print the final list using an iterator class. c) Read values from the file to create a template class of doubly linked list and print forward and backward the list. Create a member function to delete all the elements in the range 120-130. Print the shortened list using an iterator class. d) Read values from the file to create a class of circular linked list and print forward and backward the list. Search element 135 using a member function and if present replace it (and duplicates) with 150. Print the final list using an iterator class e) Code to create a linked list say having 5 nodes using static allocation. Please write in C++ and use comments explaining steps being done. // Weekly_Task2.cpp: This file contains the 'main' function. Program execution begins and ends there. #include //set basic structure for node struct node { int data; int key; struct node* next; }; //set where both sides start on NULL struct node* head = NULL; struct node* current = NULL; //void tp display the list void printList() { struct node* printList = head; printf(" [ "); //telling function to start from the beginning while (printList != NULL) { printf("%d, %d) ", printList->key, printList->data); printList = printList->next; } printf("]"); } //inserting link at the first location void insertFirst(int key, int data) { struct node* link = (struct node*)malloc(sizeof(struct node)); //types of links link->key = key; link->data = data; //point it to old first node link->next = head; //point first to new first node head = link; } //function to delete the first item in the list struct node* deleteFirst() { //save reference to first link struct node* tempLink = head; head = head->next; //return the deleted link return tempLink; } //to find if the list is empty bool isEmpty() { return head == NULL; } //to find the length of the current link int length() { int length = 0; struct node* current; for (current = head; current != NULL; current = current->next) { length++; } return length; } //find a link with given key struct node* find(int key) { //start from the first link struct node* current = head; //if list is empty if (head == NULL) { return NULL; } while (current->key != key) { //if it is last node if (current->next == NULL) { return NULL; else { current = current->next; } } //if data found, return the current Link return current; } *DELETE IS NOT WORKING EVEN THOUGH IT IS 1/delete a link with given key DESIGNATED TO A POINTER* struct node* delete(int key) { //start from the first link struct node* current = head; struct node* previous = NULL; //if list is empty if (head == NULL) { return NULL; } 1avigate through list while (current->key != key) { //if it is last node if (current->next == NULL) { return NULL; } else { //store reference to current link previous = current; //move to next link current = current->next; } } == if (current head) { //change first link to point to next link head = head->next; } else { previous->next = current->next; } return current; } void sort() { int i, j, k, tempkey, tempData; struct node* current; struct node* next; int size = length(); k = size; for (i = 0; i next; for (j = 1; j data > next->data) { tempData = current->data; current->data = next->data; next->data = tempData; tempkey = current->key; current ->key = next ->key; next->key = tempkey; } current = current->next; next = next->next; } } } // reverse the order void reverse(struct node** head_ref) { struct node* prev = NULL; struct node* current = *head_ref; struct node* next; while (current != NULL) { next = current->next; current->next = prev; prev = current; current = next; } *head_ref = prev; } int main() { insertFirst(1, 10); insert First(2, 20); insertFirst(3, 30); insert First(4, 1); insertFirst(5, 40); insertFirst(6, 56); printf("Original List: "); //print list printList(); while (!isEmpty()) { struct node* temp = deleteFirst(); printf(" Deleted value:"); printf("%d,%d) ", temp->key, temp->data); } printf(" List after deleting all items: "); printList(); insert First(1, 10); insert First(2, 20); insert First(3, 30); insert First(4, 1); insert First(5, 40); insertFirst(6, 56); printf(" Restored List: "); printList(); printf(" "); struct node* foundLink = find(4); if (foundLink != NULL) { printf("Element found: "); printf("%d,%d) ", foundLink ->key, foundLink->data); printf(" "); } else { printf("Element not found."); } //delete the fourth element delete(4); // *AGAIN DELETE WILL NOT WORK, I WANTED TO DELETE THE FOURTH ELEMENT, BUT WILL ONLY ALLOW DELETION OF "POINTERS" * printf("List after deleting an item: "); printList(); printf(" "); foundLink = find(4); if (foundLink != NULL) { printf("Element found: "); printf("%d, %d ", foundLink->key, foundLink->data); printf(" "); } else { printf("Element not found."); } //data to print at the end of the file printf(" "); sort(); printf("List after sorting the data: "); printList(); reverse(&head); printf(" List after reversing the data: "); printList(); }