linked list

[pinaka]

can anyone tell how to make delete function for my program.......and how can i insert more than one value .....ie whenever i insert a value ........the program inserts and then exits.....Thanks in advance!!!!

#include<iostream>

using namespace std;

class linkedlist
{
  private:
  struct node
  {
    int info;
    node *next;
  }*head;
  public:

  linkedlist()
  {
      head=NULL;
  }

  void append();
  void addatbeg();
  void addafter();
  void display();
  int count();
//  ~linkedlist();
};


void linkedlist::append()
{ int num;
cout<<"Enter info::";
cin>>num;
node *s,*temp;

if(head=NULL)
{
    temp=new node;
    temp->info=num;
    temp->next=NULL;
}
else
{
    temp=head;
    while(temp->next!=NULL)
    temp=temp->next;

    s=new node;
    s->info=num;
    s->next=NULL;
    temp->next=s;
}
}


void linkedlist::addatbeg()
{
    int num;
    cout<<"Enter info::";
    cin>>num;
    node* temp=new node;
    temp->info=num;
    temp->next=head;
    head=temp;

}

void linkedlist::addafter()
{
    int num, num1;
    cout<<"Enter data after which value::";
    cin>>num1;
    cout<<"Enter data::";
    cin>>num;
    int count=0;
    node *s,*temp;
    s=head;
    while(s->info!=num1)
    {
        s=s->next;
        count++;
    }

    temp=new node;
    temp->info=num;
    temp->next=s->next;
    s->next=temp;

}

void linkedlist::display()
{
    node *temp=head;
    cout<<endl;
    while(temp!=NULL)
    {
        cout<<temp->info<<" ";
        temp=temp->next;

    }
}

int linkedlist::count()
{
    node *s=head;
    int c=0;
    while(s)
    {
        s=s->next;
        c++;
    }
    return c;
}

int main()
{
   int ans;
    cout<<"!!!!!!!!!!!!!!MeNU!!!!!!!!!!!!"<<endl;
    cout<<"1.Add at baginning \n2.Add at last\n3.Add after some element\n4.Display\n5.Count\n6.Exit\n";
    cin>>ans;
    linkedlist l;
    switch(ans)
    {
        case 1: l.addatbeg();
                break;
        case 2:l.append();
                break;
        case 3:l.addafter();
                break;
        case 4:l.display();
                break;
        case 5:cout<<l.count()<<endl;
                break;
        case 6:return 0;
    }
}

[Philippe.Lahaie]

Check out the Loops section in this tutorial. Surround your switch case with one!

[thendrluca]

may be some memory leaks
but in general is something like this :)

#include<iostream>
using namespace std;

class linkedlist {
private:
    struct node {
        int info;
        node *next;
    } *head, *tail;
public:
    linkedlist() {
        head = tail = NULL;
    }
    ~linkedlist() {
        node* s;
        while (head) {
            s = head;
            head = head->next;
            delete s;
        }
        head = tail = NULL;
    }
    void append(int);
    void addatbeg(int);
    void addafter(int, int);
    void display();
    int count();
};

void linkedlist::append(int num) {
    node* temp = new node;
    temp->info = num;
    temp->next = NULL;

    if (tail) {
        tail->next = temp;
    } else {
        head = temp;
    }
    tail = temp;
}

void linkedlist::addatbeg(int num) {
    node* temp = new node;
    temp->info = num;
    temp->next = NULL;

    if (head) {
        temp->next = head;
    } else {
        tail = temp;
    }
    head = temp;
}

void linkedlist::addafter(int num, int num1) {
    node *s;
    node *temp = new node;
    temp->info = num;
    temp->next = NULL;

    if (tail) {
        s = head;
        while(s->info != num1) {
            s = s->next;
        }

        temp->next = s->next;
        s->next = temp;
    } else {
        head = tail = temp;
    }
}

void linkedlist::display() {
    node *s = head;
    cout << endl;
    while (s) {
        cout << s->info << " ";
        s = s->next;
    }
    cout << endl;
}

int linkedlist::count() {
    node *s = head;
    int count = 0;

    while(s) {
        s = s->next;
        count++;
    }
    return count;
}

int main()
{
    int ans, n, num, num1;
    linkedlist l;

    do {
        system("cls"); // only in windows platforms
        cout << "!!!!!!!!!!!!!MENU!!!!!!!!!!!!" << endl;
        cout << "1.Add at beginning" << endl;
        cout << "2.Add at last" << endl;
        cout << "3.Add after some element" << endl;
        cout << "4.Display" << endl;
        cout << "5.Count" << endl;
        cout << "6.Exit" << endl;
        cin >> ans;

        switch (ans) {
        case 1 :
        case 2 :
            cout << "How many want to add: "; cin >> n;
            break;
        case 3 : 
            cout << "add number : "; cin >> num;
            cout << "after number: "; cin >> num1;
            l.addafter(num, num1);
            break;
        case 4 : l.display(); break;
        case 5 : cout << endl << l.count() << endl; break;
        case 6 : return 0;
        }

        switch (ans) {
        case 1 :
        case 2 :
            for (int i = 0; i < n; i++) {
                cout << "number " << i+1 << ": "; cin >> num;
                switch(ans) {
                    case 1: l.addatbeg(num);
                    break;
                    case 2: l.append(num);
                    break;
                }
            }
            break;
        }
        system("pause"); // windows platform only
    } while (1);
}