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***drdebcol*** · 01-23-2010, 06:28 AM

List Class is pretty much the same in all programming languages. The only thing why people avoid using some classes is because of iterators. But you need to learn only basics and everything else will look so logical.
I am going to explain how to use list and i will give only integer examples, because all other types are pretty the same as integer.
So first declaring list class on the top should look like this :

Code:

# include <list>

Now let's show how to declare your list inside of the program :

Code:

list<type> name_of_the_list;

or if you want to add some values on declaring into your list :

Code:

list<int> name_of_the_list (number_of_times, number_that_shows);

"number_of_times" is a number that represent how many times "number_that_shows" will be shown in the list.
For example list output would be :

Code:

5 5 5

if you declare your list like this :

Code:

list<int> name_of_the_list (3,5);

Now let's see some functions that you can use in list :

Code:

empty     Test whether container is empty 

size             Return size 

max_size     Return maximum size

resize     Change size 

push_front     Insert element at beginning

push_back     Add element at the end

reverse     Reverse the order of elements

sort             Sort elements in container

clear             Clear content

Those are main functions, there are more, but these are basically everything that you need to use.
Now let's show some examples.
Let's read one list from the screen and write it's members backwards from user entering :

Code:

# include <iostream>

# include <cstdio>

# include <list>

using namespace std;

int main ()

{

  list<int> mylist; 

  int i,k,n;

 cin>>n;

 for (i=0;i<n;i++)

  { 

    cin>>k;

    mylist.push_front(k);

  }

  for (list<int>::iterator it=mylist.begin(); it!=mylist.end(); ++it)

    cout<<" "<<*it;

  cout<<endl;

  system("pause");

}

Basically in the for loop you can use use of iterators. At the beginning just learn it as it is and later it will be more clear when you start to use them.
Sort() function sorts list ascending. Now let's show that example :

Code:

# include <iostream>

# include <cstdio>

# include <list>

using namespace std;

int main ()

{

  list<int> mylist; 

  int i,k,n;

 cin>>n;

 for (i=0;i<n;i++)

  { 

    cin>>k;

    mylist.push_front(k);

  }

  mylist.sort();

  for (list<int>::iterator it=mylist.begin(); it!=mylist.end(); ++it)

    cout<<" "<<*it;

  cout<<endl;

  system("pause");

}

As you can see there is the problem to sort it descending. You need to use one trick. Sort it ascending and do reverse function :

Code:

# include <iostream>

# include <cstdio>

# include <list>

using namespace std;

int main ()

{

  list<int> mylist; 

  int i,k,n;

 cin>>n;

 for (i=0;i<n;i++)

  { 

    cin>>k;

    mylist.push_front(k);

  }

  mylist.sort();

  mylist.reverse();

  for (list<int>::iterator it=mylist.begin(); it!=mylist.end(); ++it)

    cout<<" "<<*it;

  cout<<endl;

  system("pause");

}

Those are some small tricks about using lists. There are much more to say about this, but for now it is enough.
Hope you like it !