C++ Tutorial/deque/deque erase

Материал из C\C++ эксперт
Перейти к: навигация, поиск

Remove all elements with values less than 50

<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 <deque>
  4. include <algorithm>

using namespace std; /* PRINT_ELEMENTS()

* - prints optional C-string optcstr followed by
* - all elements of the collection coll
* - separated by spaces
*/

template <class T> inline void PRINT_ELEMENTS (const T& coll, const char* optcstr="") {

   typename T::const_iterator pos;
   std::cout << optcstr;
   for (pos=coll.begin(); pos!=coll.end(); ++pos) {
       std::cout << *pos << " ";
   }
   std::cout << std::endl;

}

int main() {

   set<int,greater<int> > coll1;
   deque<int> coll2;
   // insert elements from 1 to 9
   for (int i=1; i<=9; ++i) {
       coll1.insert(i);
   }
   PRINT_ELEMENTS(coll1,"initialized: ");
   // transform all elements into coll2 by multiplying 10
   transform (coll1.begin(),coll1.end(),        // source
              back_inserter(coll2),             // destination
              bind2nd(multiplies<int>(),10));   // operation
   PRINT_ELEMENTS(coll2,"transformed: ");
   // Remove all elements with values less than 50
   coll2.erase(remove_if(coll2.begin(),coll2.end(), // range
                         bind2nd(less<int>(),50)),  // remove criterion
               coll2.end());
   PRINT_ELEMENTS(coll2,"removed:     ");

}</source>

initialized: 9 8 7 6 5 4 3 2 1
transformed: 90 80 70 60 50 40 30 20 10
removed:     90 80 70 60 50