Question

currentPtr. Use your code to make a boolean function findAndDelete that is given a pointer to a linked list and a value, and if the value is in the linked list, it is deleted and the function returns true. If it is not in the list, the function returns false. 8. Expand your menu to test your three new functions. When choosing to test the find or findAndDelete functions, the user will be first asked to enter the value to find or to find and delete. Depending on whether the functions returned true or false, the main program should write an appropriate message to the user. 9. Finally write a function called deleteList that will delete all nodes in the linked list and return the parameter head set to nullptr. You can add it to the menu for testing, but also put it at the end of the program to release all dynamic memory you used.

Answer 1

output

copyable code

#include<iostream>

#include<cstdio>

#include<cstdlib>

using namespace std;

class NodeType {

public:

NodeType( int = 0 );

int info;

NodeType * nextPtr;

};

NodeType::NodeType( int data )

{

info = data;

nextPtr = 0;

}

/*

* insert_node element

*/

void insert_node(NodeType **headnode, int val)

{

NodeType *current_ptr;

current_ptr = new(NodeType);

if (current_ptr == NULL)

{

cout<<"Memory not allocated "<<endl;

return;

}

else

{

current_ptr->info = val;

current_ptr->nextPtr = *headnode;

*headnode = current_ptr;

}

cout<<"Element insert_nodeed at beginning"<<endl;

}

//delete

void deleteFirst(NodeType **headnode)

{

NodeType *tempnode = *headnode;

*headnode = tempnode->nextPtr;

delete(tempnode);

tempnode = NULL;

}

//delete list

void delete_list(NodeType **headnode)

{

NodeType *tempnode = *headnode;

while (*headnode) {

*headnode = tempnode->nextPtr;

delete(tempnode);

tempnode = *headnode;

}

}

/*

*printlist list of element

*/

void printlist(NodeType *headnode)

{

NodeType *tempnode;

if (headnode == NULL) {

cout<<"Empty List"<<endl;

return;

}

tempnode = headnode;

cout<<"lilst of elements are: "<<endl;

while (tempnode != NULL)

{

cout<<tempnode->info<<"->";

tempnode = tempnode->nextPtr;

}

cout<<"NULL"<<endl;

}

/*

* Search node

*/

bool find(NodeType *headnode, int val)

{

bool flag = false;

if (headnode == NULL) {

cout<<"empty list"<<endl;

return flag;

}

NodeType *s;

s = headnode;

while (s != NULL)

{

if (s->info == val)

{

flag = true;

cout<<"Element "<<val<<" is found"<<endl;

break;

}

s = s->nextPtr;

}

if (!flag)

cout<<"Element "<<val<<" not found in the list"<<endl;

return flag;

}

void findanddelete(NodeType **headnode, int val)

{

NodeType *prev = NULL;

NodeType *curr = *headnode;

if (find(*headnode, val)) {

while (curr) {

if ((curr == *headnode) && (curr->info == val)) {

*headnode = curr->nextPtr;

delete(curr);

cout<<"Element "<<val<<" deleted element list"<<endl;

return;

}

if (curr->info == val) {

prev->nextPtr = curr->nextPtr;

delete(curr);

cout<<"Element "<<val<<" deleted from the list"<<endl;

return;

}

prev = curr;

curr = curr->nextPtr;

}

delete(curr);

cout<<"Element "<<val<<" deleted from the list"<<endl;

return;

}

cout<<"val to deleted not found on the list"<<endl;

return;

}

int main()

{

int opt, val;

NodeType *headnode = NULL;

NodeType *current_ptr;

while (1) {

cout<<"1.Add"<<endl;

cout<<"2.printlist"<<endl;

cout<<"3.Delete First"<<endl;

cout<<"4.Find & delete"<<endl;

cout<<"5.Delete List"<<endl;

cout<<"6.Quit "<<endl;

cout<<"Enter your option : ";

cin>>opt;

switch(opt) {

case 1:

cout<<"Enter the val to be insert_nodeed: ";

cin>>val;

cout<<"insert_node at Beginning: "<<endl;

insert_node(&headnode, val);

cout<<endl;

break;

case 2:

cout<<"Display link list element"<<endl;

printlist(headnode);

cout<<endl;

break;

case 3:

cout<<"Deleting Node at the begining: "<<endl;

deleteFirst(&headnode);

cout<<endl;

break;

case 4:

cout<<"Enter the node val to deleted: "<<endl;

cin>>val;

findanddelete(&headnode, val);

break;

case 5:

cout<<"Delete list:"<<endl;

delete_list(&headnode);

cout<<endl;

break;

case 6:

cout<<"Quiting..."<<endl;

delete_list(&headnode);

exit(1);

break;

default:

cout<<"Wrong option"<<endl;

}

}

}