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2010-05-25T14:21:17Z

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2010-05-25T10:29:43Z

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==Demonstrating push_heap, pop_heap, make_heap and sort_heap.==

<source lang="cpp">#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
int main(){
const int SIZE = 10;
int a[ SIZE ] = { 3, 100, 52, 77, 22, 31, 1, 98, 13, 40 };
int i;
vector< int > v( a, a + SIZE ), v2;
make_heap( v.begin(), v.end() );
sort_heap( v.begin(), v.end() );
for ( i = 0; i < SIZE; ++i ) {
v2.push_back( a[ i ] );
push_heap( v2.begin(), v2.end() );
}

for ( i = 0; i < v2.size(); ++i ) {
cout << "\nv2 after " << v2[ 0 ] << " popped from heap\n";
pop_heap( v2.begin(), v2.end() - i );
}
cout << endl;
return 0;
}</source>

==Use pop_heap to pop next element out of the heap==

<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.
*/

#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(): ");
// pop next element out of the heap
pop_heap (coll.begin(), coll.end());
coll.pop_back();
PRINT_ELEMENTS (coll, "after pop_heap(): ");
}</source>
<pre class=codeResult>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 pop_heap(): 8 7 6 7 4 5 5 3 6 4 1 2 3</pre>

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в 14:21, 25 мая 2010

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