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#include <iostream>
using namespace std;
class floatlist
{
private:
int element;
class listnode
{
friend class floatlist;
float value;
listnode*next; // declare the the nest node
listnode (float value1, listnode *next1=NULL)
{
value = value1;
next = next1;
}
};
//
// DECLARE listnode HEAD POINTER
// ADD STATEMENT 6 BELOW
listnode *head;
//
// DECLARE PUBLIC VARIABLES
public:
// CONSTRUCTOR FOR CLASS floatlist
floatlist()
{
head = NULL;
}
void appendnode(float);
//
void deletenode(float);
int getIndex();
void displaylist();
};
void floatlist::appendnode(float num)
{
if(head==NULL)
head= new listnode(num);
//
// HEAD NOT EMPTY
else
{
// HEAD NOT EMPTY = CREATE A SECOND POINTER
// ADD STATEMENT 8 BELOW
listnode *nodeptr; //
//
// ASSIGN HEAD VALUE TO SECOND POINTER
// ADD STATEMENT 9 BELOW
nodeptr = head; // asstign the head value to the second pointer
while (nodeptr ->next!=NULL)
nodeptr=nodeptr ->next; // go through list until a null pointer is found
//
// NULL POINTER FOUND, ADD NEW NODE
// ADD STATEMENT 11 BELOW
nodeptr->next = new listnode (num); // Null pointer found, add new node
}
}
//
// DEFINE FUNCTION displaylist
// IT IS A MEMBER OF THE CLASS floatlist
void floatlist::displaylist()
{
// CREATE A SECOND POINTER
listnode *nodeptr;
//
// // ASSIGN HEAD VALUE TO SECOND POINTER
nodeptr=head;
//
// IF THE LIST IS EMPTY, DO NOTHING.
// ADD STATEMENTS 13
if(!head)
cout<<"NO DATA IN THE LINKED LIST.";
//
//
// OUTPUT DATA AS LONG AS NODE IS NOT NULL
// ADD STATEMENTS 14
while (nodeptr)
{
cout<<nodeptr->value<<endl;
nodeptr=nodeptr->next;
}
}
// DEFINE FUNCTION deletenode
// IT IS A MEMBER OF THE CLASS floatlist
// RECEIVES THE NUMBER TO BE DELETED FROM THE LIST
void floatlist::deletenode(float num)
{
// DECLARE TWO NODE POINTERS
// ADD STATEMENT 16 BELOW
listnode *nodeptr, *previousnodeptr; //
//
// IF THE LIST IS EMPTY, DO NOTHING.
if(!head)
{
cout << "NO DATA IN THE LINKED LIST.\n";
return;
}
//
// DETERMINE IF THE FIRST NODE IS THE ONE TO DELETE.
// ADD STATEMENTS 17 BELOW
if (head-> value == num) //determines ifthe first node is the one to delete
{
nodeptr = head; //assign head to pointer
head = head -> next; //assign head as next node
delete nodeptr; //delete the pointer, the node immediately following head is
//what gets deleted
}
//
// FIRST NODE IS NOT THE ONE TO BE DELETED
else
{
//INITIALIZE nodeptr TO HEAD OF LIST
nodeptr = head;
//
// SKIP ALL NODES WHOSE VALUE MEMBER IS NOT EQUAL TO num
// ADD STATEMENTS 18 BELOW
while (nodeptr != NULL && nodeptr -> value != num) //while the pointer is not null
//and it's not the value we are looking for
{
previousnodeptr = nodeptr; // then assign current node to previuos node
nodeptr = nodeptr -> next; //and advance to the next node
}
// FOUND THE NUMBER TO BE DELETED. LINK THE PREVIOUS NOVE
// TO THE NODE AFTER nodeptr, THEN DELETE nodeptr
// ADD STATEMENTS 19 BELOW
if (nodeptr)
{
previousnodeptr -> next = nodeptr -> next; //the previous node pointer is the address of the next poniner
delete nodeptr; //delete the node pointer, not the value held in node
}
}
}
int floatlist::getIndex()
{
listnode *nodeptr = head;
int index = 0;
//O(n) search
cout<<" Enter number to be found in list: ";
cin>>element;
while(nodeptr!= NULL)
{
if(nodeptr->value== element)
{
return index;
}
nodeptr = nodeptr->next;
index++;
}
//print out a not found or some other error handling
return -1; //or something equally poignant
}
//This is the other file floatlist.h. Open it to see the other
//functions that this program will use. It will work like
//other #include libraries. Main will compile this file automatically.
//
// DECLARE USERCOMMENTS FUNCTION
// THE FUNCTION DOES NOT RECEIVE OR RETURN DATA
void usercomments(void);
//
// START MAIN
int main()
{
//
// CALL FUNCTION usercomments
usercomments();
//
// DECLARE AN OBJECT OF THE CLASS floatlist NAMED list
// ADD STATEMENT 2 BELOW
floatlist list; // Calls the object also giving it it the name of list
// this operation allows int main to communicate with the headerfile
// files
//
// DECLARE VARIABLES
int operations; // WHAT OPERATION TO BE DONE (Start or Stop)
int choice; // ADD DATA, DELETE DATA, DISPLAY DATA, EXIT
float value;
int curNode; // NUMBER TO BE ADDED TO THE LINKED LIST
//
do
{
cout<< "\nChoose an option below: \n";
cout<< "\t1) Add data.\n";
cout<< "\t2) Delete data.\n";
cout<< "\t3) Display data. \n";
cout<< "\t4) Search. \n;";
cout<< "\t5) Exit. \n\n";
cout << "Enter your choice ( 1, 2, 3, or 4): ";
cin>>choice;
//
if (choice >=1 && choice <=4)
{
// WHICH CHOICE DID USER SPECIFY?
switch(choice)
{
// ADD DATA
case 1:
cout << "\nEnter a numerical value (-1 to Stop): " << endl;
cin>>value;
while (value != -1)
{
//
// ACCESS THE appendnode FUNCTION INSIDE THE CLASS floatlist
// ADD STATEMENT 3 BELOW
list.appendnode(value);// name list is the name given the headerfile
// appendnode points to the headerfile
//list and value belong to main. appendnode
//is in header file and receive user value.
cout << "Enter a numberical value (-1 to Stop): "<<endl;
cin>>value;
}
break;
//
// DISPLAY DATA
case 2: cout<< "\nEnter a number in the list to delete: "<<endl;
cin>>value;
// ACCESS THE deletenode FUNCTION INSIDE THE CLASS floatlist
// ADD STATEMENT 15 BELOW
list.deletenode(value);
break;
//
//
// DELETE DATA
case 3:
cout<<"\nNumbers in the linked list are as follows: \n";
// ACCESS THE displaylist FUNCTION INSIDE THE CLASS floatlist
// ADD STATEMENT 12 BELOW
list.displaylist(); //calls displaylist function in the floatlist.h
cout<<"\n";
break;
//
// EXIT
case 4:
cout<<"Value was found in the list position ";
list.getIndex();
break;
case 5:
cout<<"\n\n\nProgram terminated successfully!\n\n\n";
system("pause");
break;
} // end case
}
else if (choice != 4)
{
cout << "\nThe valid choices are 1 through 4.\n";
cout << "\nSelect one of the valid choices.\n";
}
} while (choice != 4); // loop for more data
//
return 0;
system("pause");
// DISPLAY TERMINATION MESSAGE
cout<<"\n\n\nProgram terminated successfully!\n\n\n";
} // END MAIN
//
//
// DEFINE FUNCTION usercomments
void usercomments(void)
{
cout<<"This program uses a linked list. The user has the options to"
<<"\nadd data to the list, delete data from the list, or display"
<<"\nthe contents of the list.\n\n";
}
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