algo/partition1.cpp

The following code example is taken from the book
The C++ Standard Library - A Tutorial and Reference, 2nd Edition
by Nicolai M. Josuttis, Addison Wesley Longman, 2012
Copyright © 2012 by Pearson Education, Inc. and Nicolai M. Josuttis


#include "algostuff.hpp"
using namespace std;

int main()
{
   vector<int> coll1;
   vector<int> coll2;

   INSERT_ELEMENTS(coll1,1,9);
   INSERT_ELEMENTS(coll2,1,9);
   PRINT_ELEMENTS(coll1,"coll1: ");
   PRINT_ELEMENTS(coll2,"coll2: ");
   cout << endl;

   // move all even elements to the front
   vector<int>::iterator pos1, pos2;
   pos1 = partition(coll1.begin(), coll1.end(),         // range
                    [](int elem){                        // criterion
                        return elem%2==0;
                    });
   pos2 = stable_partition(coll2.begin(), coll2.end(),  // range
                           [](int elem){                // criterion
                               return elem%2==0;
                           });

   // print collections and first odd element
   PRINT_ELEMENTS(coll1,"coll1: ");
   cout << "first odd element: " << *pos1 << endl;
   PRINT_ELEMENTS(coll2,"coll2: ");
   cout << "first odd element: " << *pos2 << endl;
}