C++/STL Algorithms Heap/sort heap
Sort a heap
#include <iostream>
using std::cout;
using std::endl;
#include <algorithm>
#include <vector>
#include <iterator>
int main()
{
int a[ 10 ] = { 3, 100, 52, 77, 22, 31, 1, 98, 13, 40 };
std::vector< int > v( a, a + 10 ); // copy of a
std::vector< int > v2;
std::ostream_iterator< int > output( cout, " " );
std::copy( v.begin(), v.end(), output );
std::make_heap( v.begin(), v.end() );
std::sort_heap( v.begin(), v.end() );
cout << "\n\n";
std::copy( v.begin(), v.end(), output );
cout << endl;
return 0;
}
/*
3 100 52 77 22 31 1 98 13 40
1 3 13 22 31 40 52 77 98 100
*/
Use sort_heap to convert heap into a sorted collection(after the call it is no longer a heap)
/* 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 <vector>
#include <deque>
#include <list>
#include <set>
#include <map>
#include <string>
#include <algorithm>
#include <iterator>
#include <functional>
#include <numeric>
/* 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;
}
/* INSERT_ELEMENTS (collection, first, last)
* - fill values from first to last into the collection
* - NOTE: NO half-open range
*/
template <class T>
inline void INSERT_ELEMENTS (T& coll, int first, int last)
{
for (int i=first; i<=last; ++i) {
coll.insert(coll.end(),i);
}
}
using namespace std;
int main()
{
vector<int> coll;
INSERT_ELEMENTS(coll,3,7);
INSERT_ELEMENTS(coll,5,9);
INSERT_ELEMENTS(coll,1,4);
PRINT_ELEMENTS (coll, "on entry: ");
// convert collection into a heap
make_heap (coll.begin(), coll.end());
PRINT_ELEMENTS (coll, "after make_heap(): ");
/* convert heap into a sorted collection
* - NOTE: after the call it is no longer a heap
*/
sort_heap (coll.begin(), coll.end());
PRINT_ELEMENTS (coll, "after sort_heap(): ");
}
/*
on entry: 3 4 5 6 7 5 6 7 8 9 1 2 3 4
after make_heap(): 9 8 6 7 7 5 5 3 6 4 1 2 3 4
after sort_heap(): 1 2 3 3 4 4 5 5 6 6 7 7 8 9
*/