Re: Link List

From:
Piyo <cybermax_69@yahoo.com>
Newsgroups:
comp.lang.c++
Date:
Thu, 22 Feb 2007 06:41:24 GMT
Message-ID:
<oWaDh.128$8x.110@newssvr14.news.prodigy.net>
Jack wrote:

Ok, so below is a little code I just wrote up. I am wondering when I
delete temp2, does it actually delete all the data that temp2 is
pointing to or not?

#include <iostream>

using namespace std;


Even though it is a struct, you should
add a constructor so that you can help
debug stuff

struct myStruct {

myStruct() : Id(-1), visited(false), next(NULL) {}

     int Id;
    bool visited;
    myStruct *next;
};

int main (){
    myStruct *head = NULL;
    myStruct *temp2 = NULL;
    myStruct *temp = new myStruct;

    head = temp;
    cout << "Now creating the links\n";
    for (int i = 0; i < 10; i++){
        temp->Id = i;
        temp->visited = false;
        cout << temp->Id << " ";
        temp2 = temp;
        temp = new myStruct;
        temp2->next = temp;
    }
I think that at the end of this look you have 11
nodes: 0 to 9 and 1 containing garbage as an id and
next points to never-never land since you do not have
a constructor. Add the constructor and make sure you
only create 10 nodes. (that is left to you as an
exercise.)

        //LETS SAY WE WANT TO DELETE ITEM NUMBER 6
    temp = head;
    cout << "\nNow deleting the link 6\n";
    while ( (temp->next != NULL) && (temp->Id !=5) ){
        cout << temp->Id << " ";
        temp = temp->next;
    }
    temp2 = temp->next;
    temp->next = temp->next->next;
    delete (temp2); //DOES THIS DELETE ALL THE DATA THAT
TEMP2 IS POINTING TO?

Yes, you are doing the unlinking and deletion correctly here.

     cout << "\nNow reprinting... \n";
    temp = head;
    while(temp->next != NULL){
        cout << temp->Id << " ";
        temp = temp->next;
    }
This really should core dump right here since your last node
points to something other than NULL (most likely).

Good Luck with your project!

     return 0;
}

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