heap
說明如何使用堆積 Visual C++ 標準樣板程式庫 (STL) 函式。
template<class RandomAccessIterator> inline
void make_heap(
RandomAccessIterator First,
RandomAccessIterator Last
)
template<class RandomAccessIterator> inline
void sort_heap(
RandomAccessIterator First,
RandomAccessIterator Last
)
template<class RandomAccessIterator> inline
void push_heap(
RandomAccessIterator First,
RandomAccessIterator Last
)
template<class RandomAccessIterator> inline
void pop_heap(
RandomAccessIterator First,
RandomAccessIterator Last
)
備註
注意事項 |
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在原型中的類別/參數名稱不相符的標頭檔中的版本。某些已修改以提高可讀性。 |
堆集是一系列的組織,例如二進位樹狀目錄中的項目。堆積中的每個元素會對應至樹狀節點。在序列中的第一個值 [First...Last) 是根目錄,而是在堆積中的最大值。堆積中的每個項目滿足下列: 每個項目小於或等於其父系。最大的項目會儲存在根目錄中,按住所有子系變得較小的值。Make_heap 函式將轉換的範圍 [First...Last) 堆積。Sort_heap 函式排序以建立一系列make_heap函式。Push_heap 函式的堆積中插入新的值。Pop_heap 函式交換所指定的堆積中的第一個和最後一個項目 [First, Last),然後再降低然後再還原堆積屬性的其中一個序列的長度。堆積的 nonpredicate 版本的函式使用運算子 < 進行比較。
範例
// heapfunc.cpp
// compile with: /EHsc
//
// Functions:
// make_heap : convert a sequence to a heap
// sort_heap : sort a heap
// push_heap : insert an element in a heap
// pop_heap : remove the top element from a heap
// disable warning C4786: symbol greater than 255 characters,
// okay to ignore
#pragma warning(disable: 4786)
#include <iostream>
#include <algorithm>
#include <functional>
#include <vector>
using namespace std;
int main()
{
const int VECTOR_SIZE = 8 ;
// Define a template class vector of int
typedef vector<int > IntVector ;
//Define an iterator for template class vector of strings
typedef IntVector::iterator IntVectorIt ;
IntVector Numbers(VECTOR_SIZE) ;
IntVectorIt it ;
// Initialize vector Numbers
Numbers[0] = 4 ;
Numbers[1] = 10;
Numbers[2] = 70 ;
Numbers[3] = 10 ;
Numbers[4] = 30 ;
Numbers[5] = 69 ;
Numbers[6] = 96 ;
Numbers[7] = 100;
// print content of Numbers
cout << "Numbers { " ;
for(it = Numbers.begin(); it != Numbers.end(); it++)
cout << *it << " " ;
cout << " }\n" << endl ;
// convert Numbers into a heap
make_heap(Numbers.begin(), Numbers.end()) ;
cout << "After calling make_heap\n" << endl ;
// print content of Numbers
cout << "Numbers { " ;
for(it = Numbers.begin(); it != Numbers.end(); it++)
cout << *it << " " ;
cout << " }\n" << endl ;
// sort the heapified sequence Numbers
sort_heap(Numbers.begin(), Numbers.end()) ;
cout << "After calling sort_heap\n" << endl ;
// print content of Numbers
cout << "Numbers { " ;
for(it = Numbers.begin(); it != Numbers.end(); it++)
cout << *it << " " ;
cout << " }\n" << endl ;
//insert an element in the heap
Numbers.push_back(7) ;
push_heap(Numbers.begin(), Numbers.end()) ;
// you need to call make_heap to re-assert the
// heap property
make_heap(Numbers.begin(), Numbers.end()) ;
cout << "After calling push_heap and make_heap\n" << endl ;
// print content of Numbers
cout << "Numbers { " ;
for(it = Numbers.begin(); it != Numbers.end(); it++)
cout << *it << " " ;
cout << " }\n" << endl ;
// remove the root element from the heap Numbers
pop_heap(Numbers.begin(), Numbers.end()) ;
cout << "After calling pop_heap\n" << endl ;
// print content of Numbers
cout << "Numbers { " ;
for(it = Numbers.begin(); it != Numbers.end(); it++)
cout << *it << " " ;
cout << " }\n" << endl ;
}
Output
Numbers { 4 10 70 10 30 69 96 100 }
After calling make_heap
Numbers { 100 30 96 10 4 69 70 10 }
After calling sort_heap
Numbers { 4 10 10 30 69 70 96 100 }
After calling push_heap and make_heap
Numbers { 100 69 96 30 4 70 10 10 7 }
After calling pop_heap
Numbers { 96 69 70 30 4 7 10 10 100 }
需求
標頭: <algorithm>