C++/List/list unique
Demonstrating the STL list unique functions
#include <iostream>
#include <cassert>
#include <string>
#include <list>
using namespace std;
int main()
{
string s("Stroustrup");
list<char> list1(s.begin(), s.end());
list1.sort();
list1.unique();
list<char>::iterator i;
for (i = list1.begin(); i != list1.end(); ++i)
cout << *i;
return 0;
}
/*
Soprstu
*/
Remove duplicates
/* The following code example is taken from the book
* "The C++ Standard Library - A Tutorial and Reference"
* by Nicolai M. Josuttis, Addison-Wesley, 1999
*
* (C) Copyright Nicolai M. Josuttis 1999.
* Permission to copy, use, modify, sell and distribute this software
* is granted provided this copyright notice appears in all copies.
* This software is provided "as is" without express or implied
* warranty, and with no claim as to its suitability for any purpose.
*/
#include <iostream>
#include <list>
#include <algorithm>
#include <iterator>
using namespace std;
void printLists (const list<int>& l1, const list<int>& l2)
{
cout << "list1: ";
copy (l1.begin(), l1.end(), ostream_iterator<int>(cout," "));
cout << endl << "list2: ";
copy (l2.begin(), l2.end(), ostream_iterator<int>(cout," "));
cout << endl << endl;
}
int main()
{
// create two empty lists
list<int> list1, list2;
// fill both lists with elements
for (int i=0; i<6; ++i) {
list1.push_back(i);
list2.push_front(i);
}
printLists(list1, list2);
// sort second list, assign to list1 and remove duplicates
list2.sort();
list1 = list2;
list2.unique();
printLists(list1, list2);
}
/*
list1: 0 1 2 3 4 5
list2: 5 4 3 2 1 0
list1: 0 1 2 3 4 5
list2: 0 1 2 3 4 5
*/
Removing Duplicates from Lists
#include <algorithm>
#include <iostream>
#include <list>
#include <string>
#include <utility>
using namespace std;
void print_message( const pair<int,string>& message );
int main( )
{
list< pair< int, string > > message;
message.push_back( make_pair( 1, "A" ) );
message.push_back( make_pair( 2, "B" ) );
message.push_back( make_pair( 3, "C" ) );
message.push_back( make_pair( 4, "M" ) );
message.push_back( make_pair( 4, "M" ) );
message.push_back( make_pair( 4, "M" ) );
for_each( message.begin(), message.end(), print_message );
message.unique();
for_each( message.begin(), message.end(), print_message );
message.sort();
message.unique();
for_each( message.begin(), message.end(), print_message );
}
void print_message( const pair<int,string>& message ){
cout << message.first << " - " << message.second << endl;
}