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Question:

Duke12

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Karma Points: 2,026

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posted by Duke12 on 7/21/2008 12:38:28 PM | status: Live

creating a link list c++

Course	Textbook	Chapter	Problem
N/A	N/A	N/A	N/A

Question Details:

xTest.txt looks like:
Z
z
C
c
b
B

and yTest.txt looks like:
A
b
D
e
f
g
i
j
l
n
P
r
T
u
W
Z
a
c
D
G
i
k
m
O
q
s
U
V
y

Part 1) Implement a main.cpp that create linked list. Then read files of the the same format as xTest.txt, insert each character into the linked list. After all elemenets of the file are inserted in the list display the entire list. Then delete the entire list. To sort upper and lower case, toupper, could be useful.

Output Example:

The list now contains:



B



b



C



c



Z



z







Deleting the list:



Deleting element B



Deleting element b



Deleting element C



Deleting element c



Deleting element Z



Deleting element z



Deletion complete







Press any key to continue . . .







And the yTest outputs what it is in like the output above

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Tags: Computer Science, Data Structures

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Answers:

sam_GT

Expert

Karma Points: 811

Private Message

posted by sam_GT on 7/22/2008 1:02:17 AM | status: Live

Asker's Rating: Helpful

Duke12's comment:

"thanks for the help"

Response Details:

//compiled in g++ compiler

#include<iostream.h>

#include<stdio.h>

#include<ctype.h>

int insert_node(char ch);

int l_alpha(char ch) // to find is it lower or upper alpahbat

{

if(ch >= 'a' && ch <='z')

return 1;

else

return 0;

}



int u_alpha(char ch)

{

if(ch >= 'A' && ch <='Z')

return 1;

else

return 0;

}

struct node

{

char ch;

struct node *next;

}*first,*last,*ptr; //list of ch

int delete_nodes(struct node *ptr) //function that will delete all nodes

{

struct node *tptr;



cout<<"Deleting the list:\n";

while(ptr != NULL)

{

tptr= ptr;

ptr=ptr->next;

cout<<"Deleting element "<<tptr->ch<<"\n";

delete tptr;

}

}

int main()

{

char ch;

FILE *fp;

fp = fopen("xTest.txt","r");

while((ch=fgetc(fp) ) != EOF)

{

insert_node(ch); // insert node in the list

}

fclose(fp);

ptr=first;



cout<<"\n\n\nThe list now contains:\n";

while(ptr != NULL)

{

cout<<"\n "<<ptr->ch;

ptr=ptr->next;

}

cout<<"\n";

delete_nodes(first);

first=NULL;

fp = fopen("yTest.txt","r");

while((ch=fgetc(fp) ) != EOF)

{

insert_node(ch);

}

fclose(fp);

ptr=first;



cout<<"The list now contains:\n";

while(ptr != NULL)

{

cout<<"\n "<<ptr->ch;

ptr=ptr->next;

}

cout<<"\n";

delete_nodes(first);





}



int insert_node(char ch)

{

struct node *tptr;

char CH;

if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) //valid ch or not

{



}else

{

return -1;

}





if(first ==NULL)// first node insertion

{

first = last = (struct node*)new struct node;

last->ch = ch;

last->next = NULL;

}else

{

ptr= first;

while(ptr !=NULL)

{

if((ch >= 'a' && ch <= 'z'))

{

if((ptr->ch >= 'a' && ptr->ch <= 'z'))

{

tptr=ptr->next;

if(tptr != NULL)

{

if(ch>= ptr->ch && ch <= tptr->ch && l_alpha(tptr->ch))

break;

if(ch>= ptr->ch && toupper(ch) <= tptr->ch && u_alpha(tptr->ch))

break;

}



}

else

{

tptr=ptr->next;



CH=toupper(ch);	

if(tptr == NULL)

{

if( ch <= tolower(ptr->ch))

break;

}else

{

if(CH >= ptr->ch && ch <= tptr->ch && l_alpha(tptr->ch))

break;	

else

if(CH >= ptr->ch && CH <= tptr->ch && u_alpha(tptr->ch))

break;



}

}

}

if((ch >= 'A' && ch <= 'Z'))

{

if((ptr->ch >= 'A' && ptr->ch <= 'Z'))

{

tptr=ptr->next;

if(tptr!=NULL)

{

if(ch>= ptr->ch && ch <= tptr->ch && u_alpha(tptr->ch) )

break;

if(ch>= ptr->ch && tolower(ch) <= tptr->ch && l_alpha(tptr->ch) )

break;

}



}

else

{

tptr=ptr->next;



CH=toupper(ptr->ch);	

if(tptr == NULL)

{

}else

{

if(ch > CH && ch <= tptr->ch && u_alpha(tptr->ch))

break;	

else

if(ch > CH && tolower(ch) <= tptr->ch && l_alpha(tptr->ch))

break;



}





}

}



last=ptr;

ptr=ptr->next;

}

if(ptr ==NULL)

{

if(l_alpha(ch) && l_alpha(first->ch))

{

if(ch <= first->ch)

{

tptr=first;

ptr = (struct node*)new struct node;

ptr->ch = ch;

ptr->next = tptr;

first = ptr;

return 0;

}

}

else

{

if(u_alpha(ch) && u_alpha(first->ch))

{

if(ch <= first->ch)

{

tptr=first;

ptr = (struct node*)new struct node;

ptr->ch = ch;

ptr->next = tptr;

first = ptr;

return 0;

}

}

else

{

if(l_alpha(ch) && u_alpha(first->ch))

{

ch=toupper(ch);

if(ch <= first->ch)

{

tptr=first;

ptr = (struct node*)new struct node;

ptr->ch = tolower(ch);

ptr->next = tptr;

first = ptr;

return 0;

}ch=tolower(ch);

}

else	

{

if(u_alpha(ch) && l_alpha(first->ch))

{

ch=tolower(ch);

if(ch <= first->ch)

{

tptr=first;

ptr = (struct node*)new struct node;

ptr->ch = toupper(ch);

ptr->next = tptr;

first = ptr;

return 0;

}ch=toupper(ch);

}





}		





}

}

last->next = (struct node*)new struct node;

last = last->next;

last->ch = ch;

last->next = NULL;

}else

{

tptr=ptr->next;

ptr->next = (struct node*)new struct node;

ptr = ptr->next;

ptr->ch = ch;

ptr->next = tptr;



}

}

}

Tags: Computer Science, Data Structures

Duke12

Guru

Karma Points: 2,026

Private Message

posted by Duke12 on 7/22/2008 1:48:38 AM | status: Live

Asker's Rating: N/A-Posted by Person Asking Question

Response Details:

thanks...I have the code for part 1 but what I need help on now is the outputting what element is being deleted. I have it not outputting anything

Part1.cpp

#include "part1.h"
#include <iostream>
using namespace std;

void part1::appendList(char num)
{
   listNode *newNode;
   listNode *nodePtr;

   newNode = new listNode;
   newNode->letter = num;
   newNode->next = NULL;

   if(!head)
       head = newNode;
   else
   {
       nodePtr = head;

       while(nodePtr->next)
           nodePtr = nodePtr->next;

       nodePtr->next = newNode;
   }
}

void part1::displayList() const
{
   listNode *nodePtr; // move through the list

   nodePtr = head; //position nodePtr at head of the list

   while(nodePtr)
   {
       cout << nodePtr->letter << endl;//display value

       nodePtr = nodePtr->next;//move to next node
   }
}

void part1::insertNode(char num)
{
   // get a new node to insert
   listNode *newNode;
   listNode *nodePtr; // to traverse the list
    listNode *previousNode = NULL; // the previous node
   // allocate a new node
   newNode= new listNode;
   newNode->letter=num;

   if(!head)
   {
       head = newNode;
        newNode->next=NULL;
   }
   else
   {
       nodePtr = head;
       previousNode= NULL;

      while ( nodePtr!=NULL && toupper(nodePtr->letter) <= toupper (num))
      {
         if (nodePtr->letter >num&&toupper (nodePtr->letter) == toupper (num))   //current is the last in list
         {
               break;
         }
              previousNode = nodePtr;
              nodePtr=nodePtr->next;

      }
       if(previousNode ==NULL)
       {
           head=newNode;
           newNode->next=nodePtr;
       }
       else
       {
           previousNode->next=newNode;
           newNode->next=nodePtr;
       }

      }

   }

part1::~part1()
{
   listNode *nodePtr;
   listNode *nextNode;
   cout << "Deleting the list" << endl;
   nodePtr=head;

   while(nodePtr != NULL)
   {
       nextNode=nodePtr->next;
       cout << "Deleting Element:" << endl;
       delete nodePtr;
       nodePtr=nextNode;
   }
   cout << "Deleting complete" << endl;
}

main.cpp
#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>
#include "part1.h"

using namespace std;

int main()
{
   char name;
   ifstream infile;
   infile.open("demoTest.txt");
   part1 list;

if(!infile)
   cout << "Can not open file" << endl;
else
{
   infile >> name;

   while(infile)
   {
       list.insertNode(name);
       infile >> name;
   }

   cout << "The list now contains:" << endl;
   list.displayList();
}
   return 0;
}

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Tags: Computer Science, Data Structures

APPOLLO

Apprentice

Karma Points: 116

Private Message

posted by APPOLLO on 7/22/2008 2:25:05 AM | status: Live

Asker's Rating: Helpful

Duke12's comment:

"thanks"

Response Details:

while(nodePtr != NULL)
{

        nodePtr=nextNode;
        cout << "Deleting Element:" << endl;
        nextNode=nextNode->next;

delete nodePtr;
}

Hi, you should change the sequence of your sentences and make some changes, since u need to change the pointer to the next element first and then delete the previous element. Otherwise, you will not get the value which element pointer points to. Check it again!

Tags: Computer Science, Data Structures