C++ Tutorial/set multiset/multiset erase

Demonstrating multiset erase a found element

<source lang="cpp">#include <iostream>

1. include <cassert>
2. include <list>
3. include <string>
4. include <set>

using namespace std;

1. include <functional>

int main() {

 string s("There is no distinctly native American criminal class");
 list<char> list1(s.begin(), s.end());
 // Put the characters in list1 into multiset1:
 multiset<char> multiset1;
 copy(list1.begin(), list1.end(),inserter(multiset1, multiset1.end()));
 multiset1.erase("a");
 multiset<char>::iterator i = multiset1.find("e");
 multiset1.erase(i);

 multiset<char>::iterator k;
 for (k = multiset1.begin(); k != multiset1.end(); ++k)
   cout << *k;
 return 0;

}</source>

ATccccdeeehiiiiiiilllmmnnnnnorrrsssstttvy"

Demonstrating multiset erase functions

<source lang="cpp">#include <iostream>

1. include <cassert>
2. include <list>
3. include <string>
4. include <set>

using namespace std;

1. include <functional>

int main() {

 string s("There is no distinctly native American criminal class");
 list<char> list1(s.begin(), s.end());
 // Put the characters in list1 into multiset1:
 multiset<char> multiset1;
 copy(list1.begin(), list1.end(),inserter(multiset1, multiset1.end()));
 multiset1.erase("a");
 multiset<char>::iterator k;
 for (k = multiset1.begin(); k != multiset1.end(); ++k)
   cout << *k;
 return 0;

}</source>

ATccccdeeeehiiiiiiilllmmnnnnnorrrsssstttvy"

Demonstrating multiset erase functions: erase a range

<source lang="cpp">#include <iostream>

1. include <cassert>
2. include <list>
3. include <string>
4. include <set>

using namespace std;

1. include <functional>

int main() {

 string s("There is no distinctly native American criminal class");
 list<char> list1(s.begin(), s.end());
 // Put the characters in list1 into multiset1:
 multiset<char> multiset1;
 copy(list1.begin(), list1.end(),inserter(multiset1, multiset1.end()));
 multiset1.erase("a");
 multiset<char>::iterator i = multiset1.find("e");
 multiset<char>::iterator j = multiset1.find("v");
 multiset1.erase(i, j);

 multiset<char>::iterator k;
 for (k = multiset1.begin(); k != multiset1.end(); ++k)
   cout << *k;
 return 0;

}</source>

ATccccdvy"

erase from begin() to end()

<source lang="cpp">#include <algorithm>

1. include <iostream>
2. include <set>
3. include <string>
4. include <vector>

using namespace std; template <class T> void print(T& c){

  for( typename T::iterator i = c.begin(); i != c.end(); i++ ){
     std::cout << *i << endl;
  }

} int main( ) {

  const int num_years = 5;
  const char* d[num_years] = { "A", "B","C", "D", "E" };
  const char* d2[num_years] = { "a", "b","c", "d", "e" };
  const char* d3[num_years] = { "1","2", "3",  "4", "5" };
  multiset<string> s1( d,d+num_years );
  multiset<string> s2( d2,d2+num_years );
  multiset<string> s3( d3,d3+num_years );
  print( s1 );
  print( s2 );
  print( s3 );
  vector<string> winner;
  merge( s1.begin(), s1.end(),s2.begin(), s2.end(), back_inserter( winner ) );
  vector<string> all_winner;
  merge( winner.begin(), winner.end(),s3.begin(), s3.end(), back_inserter( all_winner ) );
  all_winner.erase( unique( all_winner.begin(), all_winner.end() ),all_winner.end() );
  cout << endl << all_winner.size() << " UNIQUE WINNERS\n";
  for( vector<string>::size_type i = 0; i < all_winner.size(); ++i )
  {
     cout << all_winner[i] << "  ";
     if( (i+1) % 5 == 0 )
        cout << endl;
  }

}</source>

Remove all elements up to element with value 3

<source lang="cpp">/* 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.
*/

1. include <iostream>
2. include <set>
3. include <algorithm>
4. include <iterator>

using namespace std; int main() {

   /* type of the collection:
    * - duplicates allowed
    * - elements are integral values
    * - descending order
    */
   typedef multiset<int,greater<int> > IntSet;
   IntSet coll1;        // empty multiset container
   // insert elements in random order
   coll1.insert(4);
   coll1.insert(3);
   coll1.insert(5);
   coll1.insert(1);
   coll1.insert(6);
   coll1.insert(2);
   coll1.insert(5);
   // iterate over all elements and print them
   IntSet::iterator pos;
   for (pos = coll1.begin(); pos != coll1.end(); ++pos) {
       cout << *pos << " ";
   }
   cout << endl;
   // assign elements to another multiset with ascending order
   multiset<int> coll2(coll1.begin(),
                       coll1.end());
   
   // remove all elements up to element with value 3
   coll2.erase (coll2.begin(), coll2.find(3));
   // print all elements of the copy
   copy (coll2.begin(), coll2.end(),
         ostream_iterator<int>(cout," "));
   cout << endl;

}</source>

6 5 5 4 3 2 1
3 4 5 5 6

Remove all elements with value 5

<source lang="cpp">/* 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.
*/

1. include <iostream>
2. include <set>
3. include <algorithm>
4. include <iterator>

using namespace std; int main() {

   /* type of the collection:
    * - duplicates allowed
    * - elements are integral values
    * - descending order
    */
   typedef multiset<int,greater<int> > IntSet;
   IntSet coll1;        // empty multiset container
   // insert elements in random order
   coll1.insert(4);
   coll1.insert(3);
   coll1.insert(5);
   coll1.insert(1);
   coll1.insert(6);
   coll1.insert(2);
   coll1.insert(5);
   // iterate over all elements and print them
   IntSet::iterator pos;
   for (pos = coll1.begin(); pos != coll1.end(); ++pos) {
       cout << *pos << " ";
   }
   cout << endl;
   // assign elements to another multiset with ascending order
   multiset<int> coll2(coll1.begin(),
                       coll1.end());
   
   // remove all elements with value 5
   int num;
   num = coll2.erase (5);
   cout << num << " element(s) removed" << endl;
   // print all elements of the copy
   copy (coll2.begin(), coll2.end(),
         ostream_iterator<int>(cout," "));
   cout << endl;

}</source>

6 5 5 4 3 2 1
2 element(s) removed
1 2 3 4 6