alg24.c

C++Primer中文版 第三版 深入系列 Primer 第三版 著 中中文文版版潘爱民张丽译 Addison-Wesley 中国电力出版社 www.infopower.com.cn S

// heap stuff -- need to merge

#include <algorithm>
#include <vector>
#include <assert.h>

template <class Type>
void print_elements( Type elem ) { cout << elem << " "; }
	
int main()
{
	int ia[] = {29,23,20,22,17,15,26,51,19,12,35,40 }; 
	vector< int, allocator > vec( ia, ia+12 );
		

// generates: 51 35 40 23 29 20 26 22 19 12 17 15 
	make_heap( &ia[0], &ia[12] );
        void (*pfi)( int ) = print_elements;
        for_each( ia, ia+12, pfi ); cout << "\n\n";

// generates: 12 17 15 19 23 20 26 51 22 29 35 40
        // the bentley heap: root is smallest element ...^M
	make_heap( vec.begin(), vec.end(), greater<int>() );
        for_each( vec.begin(), vec.end(), pfi ); cout << "\n\n";

// generates: 12 15 17 19 20 22 23 26 29 35 40 51 
	sort_heap( ia, ia+12 );
        for_each(  ia, ia+12, pfi ); cout << "\n\n";

	// add an additional, new smallest element:
	vec.push_back( 8 );

// generates: 8 17 12 19 23 15 26 51 22 29 35 40 20 
	// should place newest smallest element at root
	push_heap( vec.begin(), vec.end(), greater<int>() );
        for_each(  vec.begin(), vec.end(), pfi ); cout << "\n\n";

// generates: 12 17 15 19 23 20 26 51 22 29 35 40 8 
	// should replace smallest element with second smallest
	pop_heap( vec.begin(), vec.end(), greater<int>() );
        for_each( vec.begin(), vec.end(), pfi ); cout << "\n\n";

	return 0;
}