//Pg.288
#include <cassert>
#include <iostream>
using namespace std;

void deleteKthElement(int k, int& count);

int main()
{

struct nodeType {
  int info;
  nodeType *link;  
};


  nodeType *first, *newNode, *last, *traverse;  
  int num;
  int count = 0;

  cout << "Enter a list of integers ending with -999.\n";
  cin  >> num;
  first = NULL;

  while (num != -999)
  {
    newNode = new nodeType;
    assert(newNode !=NULL);

    newNode ->info = num;
    newNode ->link = NULL;

    if(first == NULL)
    {
      first = newNode;
      last = newNode;
    }
    else
    {
      last -> link = newNode;
      last = newNode;
    }
    cin >> num;
    count++;    //increment the counter to keep track of no. of elements
  } // end while  
  
  //print the linked list prior to deleting the 5th element
  cout << "The linked list before:" << endl;
  traverse = new nodeType;
  assert(traverse != NULL);
  traverse = first;
  
  while (traverse != NULL)
  {
    cout << traverse->info << endl;
    traverse = traverse->link;
  } 
  
  deleteKthElement(5,count);
 
  //print the linked list after deleting the 5th element !!
  cout << "The linked list after deleting the 5th element:" << endl;
  traverse = new nodeType;
  assert(traverse != NULL);
  traverse = first;
  
  while (traverse != NULL)
  {
    cout << traverse->info << endl;
    traverse = traverse->link;
  } 
  
}  // end main

void deleteKthElement(int k, int& count)
{
  assert(k <= count);  
  nodeType *current, *trailCurrent;
  int i;
  
  if (first ==NULL)
    cerr << "Cannot delete from an empty list!" << endl;
  else
     if (k == 1)
     {
       current = first;
       first = first->link;
       
       if (first == NULL)
          last = NULL;
       
       delete current;
     }
     else
     {
         trailCurrent = first;
         current = first->link;
         
          i = 2;
          while(i < k)
          {
            trailCurrent = current;
            current = current->link;
            i++;
          }
          
          trailCurrent->link = current->link;
          if (current == last)
            last = trailCurrent;
      }       
}

I'm struggling to get the 5th element deleted in the list
Compiler giving me a lot of errors ; eg. nodeType undeclared, etc.
Please help ?

Recommended Answers

All 6 Replies

The nodeType struct should be declared outside the main function.

I did what you said and i'm still experiencing some problems.Could you please paste the code into your compiler and run it ?
Thanks once again for your previous reply !

Thanks ... i seem to have found help .
Here's the adapted code

//Pg.288
#include <cassert>
#include <iostream>
using namespace std;

struct nodeType 
{
  int info;
  nodeType *link;  
};

void deleteKthElement(nodeType *firstElement, int k, const int& count);

int main()
{
  nodeType *first, *newNode, *last, *traverse;  
  int num;
  int count = 0;

  cout << "Enter a list of integers ending with -999.\n";
  cin  >> num;
  first = NULL;

  while (num != -999)
  {
    newNode = new nodeType;
    assert(newNode !=NULL);

    newNode ->info = num;
    newNode ->link = NULL;

    if(first == NULL)
    {
      first = newNode;
      last = newNode;
    }
    else
    {
      last -> link = newNode;
      last = newNode;
    }
    cin >> num;
    count++;    //increment the counter to keep track of no. of elements    
  } // end while  
  
  //print the linked list prior to deleting the 3rd element
  cout << "The linked list before:" << endl;
  //traverse = new nodeType;
  //assert(traverse != NULL);
  traverse = first;
  
  while (traverse != NULL)
  {
    cout << traverse->info << endl;
    traverse = traverse->link;
  } 
  
  
  deleteKthElement(first->link,2,count);
 
  //print the linked list after deleting the 3rd element 
  cout << "The linked list after deleting the 3rd element:" << endl;
  //traverse = new nodeType;
  //assert(traverse != NULL);
  traverse = first;
  
  while (traverse != NULL)
  {
    cout << traverse->info << endl;
    traverse = traverse->link;
  } 
}  // end main


void deleteKthElement( nodeType *firstElement,int k, const int& count)
{
  assert(k <= count);  
  nodeType *first ,*last, *current, *trailCurrent;
  int i;
  
  first = firstElement;
  
  if (firstElement == NULL)
    cerr << "Cannot delete from an empty list!" << endl;
  else
     if (k == 1)
     {
       current = firstElement;
       firstElement = firstElement->link;
       
       if (firstElement == NULL)
          last = NULL;
       
       delete current;
     }
     else
     {
         trailCurrent = firstElement;
         current = firstElement->link;
         
          i = 2;
          while(i < k)
          {
            trailCurrent = current;
            current = current->link;
            i++;
          }
          
          trailCurrent->link = current->link;
          if (current == last)
            last = trailCurrent;
      }       
}  //end deleteKthElement
//Pg.288
#include <cassert>
#include <iostream>
using namespace std;

struct nodeType 
{
  int info;
  nodeType *link;  
};

void deleteKthElement(nodeType *firstElement, int k, const int& count);

int main()
{
  nodeType *first, *newNode, *last, *traverse;  
  int num;
  int count = 1;

  cout << "Enter a list of integers ending with -999.\n";
  cin  >> num;
  first = NULL;

  while (num != -999)
  {
    newNode = new nodeType;
    assert(newNode !=NULL);

    newNode ->info = num;
    newNode ->link = NULL;

    if(first == NULL)
    {
      first = newNode;
      last = newNode;
    }
    else
    {
      last -> link = newNode;
      last = newNode;
    }
    cin >> num;
    count++;    //increment the counter to keep track of no. of elements    
  } // end while  
  
  //print the linked list prior to deleting the 3rd element
  cout << "The linked list before:" << endl;
  //traverse = new nodeType;
  //assert(traverse != NULL);
  traverse = first;
  
  while (traverse != NULL)
  {
    cout << traverse->info << endl;
    traverse = traverse->link;
  } 
  
  
  deleteKthElement(first,2,count);
 
  //print the linked list after deleting the 2nd element 
  cout << "The linked list after deleting the 2nd element:" << endl;
  //traverse = new nodeType;
  //assert(traverse != NULL);
  traverse = first;
  
  while (traverse != NULL)
  {
    cout << traverse->info << endl;
    traverse = traverse->link;
  } 
}  // end main


void deleteKthElement( nodeType *firstElement,int k, const int& count)
{
  assert(k <= count);  
  nodeType *first ,*last, *current, *trailCurrent;
  int i = 1;
  
 // first = firstElement;
  
  if (firstElement == NULL)
    cerr << "Cannot delete from an empty list!" << endl;
  else
     if (k == 1)
     {
       current = firstElement;
       firstElement = firstElement->link;
       
       if (firstElement == NULL)
          last = NULL;
       
       delete current;
     }
     else
     {
         trailCurrent = firstElement;
         current = firstElement->link;
         
          i = 2;
          while(i < k)
          {
            trailCurrent = current;
            current = current->link;
            i++;
          }
          
          trailCurrent->link = current->link;
          if (current == last)
            last = trailCurrent;
      }       
}  //end deleteKthElement

I thought i had this problem solved but i've just one last issue:
Why is the program displaying a zero (0) after deleting the node with the smallest info ??
Note: The program seems to work fine if the node with the smallest info is not the first node in the linked list. Why is this ?
(Please refer to my attachments for the code as well as the input and output of the program)

I thought i had this problem solved but i've just one last issue:
Why is the program displaying a zero (0) after deleting the node with the smallest info ??
Note: The program seems to work fine if the node with the smallest info is not the first node in the linked list. Why is this ?
(Please refer to my attachments for the code as well as the input and output of the program)

#include <cassert>
#include <iostream>
using namespace std;

struct nodeType 
{
  int info;
  nodeType *link;  
};

void deleteKthElement(nodeType *firstElement, int k, const int& count);
void deletesmallestInfoNode(nodeType *firstType);
void deleteNode(nodeType *firstNode, const int& deleteItem);
void deletegivenInfoNode(nodeType *fNode, const int& deleteInfo);

/* ------------------------------------------------------------------------ */

int main()
{
  nodeType *first, *newNode, *last, *traverse;  
  int num;
  int count = 0;

  cout << "Enter a list of integers ending with -999.\n";
  cin  >> num;
  first = NULL;

  while (num != -999)
  {
    newNode = new nodeType;
    assert(newNode !=NULL);

    newNode ->info = num;
    newNode ->link = NULL;

    if(first == NULL)
    {
      first = newNode;
      last = newNode;
    }
    else
    {
      last -> link = newNode;
      last = newNode;
    }
    cin >> num;
    count++;    //increment the counter to keep track of no. of elements    
  } // end while  
  
  //print the linked list prior to deleting the 2nd element
  cout << "The linked list before:" << endl;
  traverse = first;  
  while (traverse != NULL)
  {
    cout << traverse->info << endl;
    traverse = traverse->link;
  } 
  
  
  deleteKthElement(first,2,count);
 
  //print the linked list after deleting the 2nd element 
  cout << "The linked list after deleting the 2nd element:" << endl;
  traverse = first;  
  while (traverse != NULL)
  {
    cout << traverse->info << endl;
    traverse = traverse->link;
  } 
  
  deletesmallestInfoNode(first);
  
  //print the linked list after deleting the node with the smallest info
  cout << "The linked list after deleting the node with the smallest info:" << endl;
  traverse = first;  
  while (traverse != NULL)
  {
    cout << traverse->info << endl;
    traverse = traverse->link;
  } 
  
   deletegivenInfoNode(first,15);
   
  //print the linked list after removing all occurences of 15 in the list 
  cout << "The linked list after deleting all occurences of 15 in the list:" << endl;
  traverse = first;  
  while (traverse != NULL)
  {
    cout << traverse->info << endl;
    traverse = traverse->link;
  }  
}  // end main

/* ------------------------------------------------------------------------ */

void deleteKthElement( nodeType *firstElement,int k, const int& count)
{
  assert(k <= count);  
  nodeType *first ,*last, *current, *trailCurrent;
  int i = 1;
  
 // first = firstElement;
  
  if (firstElement == NULL)
    cerr << "Cannot delete from an empty list!" << endl;
  else
     if (k == 1)
     {
       current = firstElement;
       firstElement = firstElement->link;
       
       if (firstElement == NULL)
          last = NULL;
       
       delete current;
     }
     else
     {
         trailCurrent = firstElement;
         current = firstElement->link;
         
          i = 2;
          while(i < k)
          {
            trailCurrent = current;
            current = current->link;
            i++;
          }
          
          trailCurrent->link = current->link;
          if (current == last)
            last = trailCurrent;
      }       
}  //end deleteKthElement


void deletesmallestInfoNode(nodeType *firstType)
{   
    nodeType *first;
    first = firstType;
    if (first == NULL)               // the list has only one node
	cerr << "Cannot delete from an empty list!" << endl;		
    else
    {
       nodeType* newNode;
       bool found = false;              
       newNode = first;         // newNode points to the first node
       
       while (newNode != NULL && !found)
        {
        if (newNode->link == NULL) //only 1 node in list or the last 
	    {
	    	 deleteNode(first,newNode->info); //call function to delete node
			 found = true;			//smallest info found !
	    }
	    else if (newNode->info <= newNode->link->info)
           {
            deleteNode(first,newNode->info); //call function to delete node
            found = true;                  //smallest info found !
           }
           else
             newNode = newNode->link; //advance newNode 
        }  // end while   
    } // endif
}//end deletesmallestInfoNode


void deleteNode(nodeType *firstNode ,const int& deleteItem)
{
    nodeType *first, *last;
	nodeType *current; //pointer to traverse the list
	nodeType *trailCurrent; //pointer just before current
	bool found;
	
	first = firstNode;

	if(first == NULL)    //Case 1; list is empty. 
		cerr<<"Cannot delete from an empty list.\n";
	else
	{
		if(first->info == deleteItem) //Case 2 
		{
			current = first;
			first = first->link;			
			if(first == NULL)    //list only had 1 node			
             	last = NULL;
     			delete current;	   
		}
		else  //search the list for the node with the given info
		{
			found = false;
			trailCurrent = first;   //set trailCurrent to point to
                                 //the first node
			current = first->link;  //set current to point to the 
    			   //second node
	
			while(current != NULL && !found)
			{
  				if(current->info != deleteItem) 
				{
					trailCurrent = current;
					current = current->link;
				}
				else
					found = true;
			} // end while

			if(found) //Case 3; if found, delete the node
			{
				trailCurrent->link = current->link;
				//count--;

				if(last == current)      //node to be deleted was 
                                     //the last node
					last = trailCurrent;  //update the value of last

				delete current;  //delete the node from the list
			}
			else
				cout<<"Item to be deleted is not in the list."<<endl;
		} //end else
	} //end else
} //end deleteNode



//function to delete all occurences of a given info in the list
void deletegivenInfoNode(nodeType *fNode, const int& deleteInfo)
{ 
   nodeType *first;
   first = fNode; 
   bool found = false;
   if (first == NULL)               // the list has only one node
	cerr << "Cannot delete from an empty list!" << endl;		
    else
    {
       nodeType *traversePtr;         //pointer to traverse the list
       traversePtr = first;         // traversePtr points to the first node
       while (traversePtr != NULL)
       { 	
         if (traversePtr->info == deleteInfo)
         {
            deleteNode(first,deleteInfo);
     		found = true; 
   		 }
         else
             traversePtr = traversePtr->link; 		//advance traversePtr
       }   // end while
     }  // end if
	
      if (!(found))
	     cout << "Item to be deleted is not in the list!" << endl; 		
 }  // end deletegivenInfoNode
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