堆数据结构可以在使用 STL 的范围内实现，这允许更快地输入到堆中，并且检索一个数字总是导致最大的数字，即每次弹出最大数量的剩余数字。堆的其他数量根据实现进行安排。
堆上的操作：
1. make_heap() :- 此函数用于将容器中的范围转换为堆。
2. front() :- 此函数显示堆的第一个元素，即最大数量。
// C++ code to demonstrate the working of
// make_heap(), front()
#include
using namespace std;
int main()
{
// Initializing a vector
vector v1 = {20, 30, 40, 25, 15};
// Converting vector into a heap
// using make_heap()
make_heap(v1.begin(), v1.end());
// Displaying the maximum element of heap
// using front()
cout << "The maximum element of heap is : ";
cout << v1.front() << endl;
return 0;
}
输出：
The maximum element of heap is : 40
3. push_heap() :- 该函数用于向堆中插入元素。堆的大小增加1。新元素适当地放置在堆中。
4. pop_heap() :- 该函数用于删除堆的最大元素。堆的大小减 1。此操作后，堆元素会相应地重新组织。
// C++ code to demonstrate the working of
// push_heap() and pop_heap()
#include
using namespace std;
int main()
{
// Initializing a vector
vector v1 = {20, 30, 40, 25, 15};
// Converting vector into a heap
// using make_heap()
make_heap(v1.begin(), v1.end());
// Displaying the maximum element of heap
// using front()
cout << "The maximum element of heap is : ";
cout << v1.front() << endl;
// using push_back() to enter element
// in vector
v1.push_back(50);
// using push_heap() to reorder elements
push_heap(v1.begin(), v1.end());
// Displaying the maximum element of heap
// using front()
cout << "The maximum element of heap after push is : ";
cout << v1.front() << endl;
// using pop_heap() to delete maximum element
pop_heap(v1.begin(), v1.end());
v1.pop_back();
// Displaying the maximum element of heap
// using front()
cout << "The maximum element of heap after pop is : ";
cout << v1.front() << endl;
return 0;
}
输出：
The maximum element of heap is : 40
The maximum element of heap after push is : 50
The maximum element of heap after pop is : 40
5. sort_heap() :- 该函数用于对堆进行排序。此操作后，容器不再是堆。
// C++ code to demonstrate the working of
// sort_heap()
#include
using namespace std;
int main()
{
// Initializing a vector
vector v1 = {20, 30, 40, 25, 15};
// Converting vector into a heap
// using make_heap()
make_heap(v1.begin(), v1.end());
// Displaying heap elements
cout << "The heap elements are : ";
for (int &x : v1)
cout << x << " ";
cout << endl;
// sorting heap using sort_heap()
sort_heap(v1.begin(), v1.end());
// Displaying heap elements
cout << "The heap elements after sorting are : ";
for (int &x : v1)
cout << x << " ";
return 0;
}
输出：
The heap elements are : 40 30 20 25 15
The heap elements after sorting are : 15 20 25 30 40
6. is_heap() :- 该函数用于检查容器是否为堆。通常，在大多数实现中，反向排序的容器被视为堆。如果容器是堆则返回真，否则返回假。
6. is_heap_until() :- 该函数将迭代器返回到位置，直到容器成为堆。通常，在大多数实现中，反向排序的容器被视为堆。
// C++ code to demonstrate the working of
// is_heap() and is_heap_until()
#include
using namespace std;
int main()
{
// Initializing a vector
vector v1 = {40, 30, 25, 35, 15};
// Declaring heap iterator
vector::iterator it1;
// Checking if container is heap
// using is_heap()
is_heap(v1.begin(), v1.end())?
cout << "The container is heap ":
cout << "The container is not heap";
cout << endl;
// using is_heap_until() to check position
// till which container is heap
auto it = is_heap_until(v1.begin(), v1.end());
// Displaying heap range elements
cout << "The heap elements in container are : ";
for (it1=v1.begin(); it1!=it; it1++)
cout << *it1 << " ";
return 0;
}
输出：
The container is not heap
The heap elements in container are : 40 30 25
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