push_heap

添加在范围的末尾与在包含范围的现有堆的元素的元素。

template<class RandomAccessIterator> 
   void push_heap( 
      RandomAccessIterator _First,  
      RandomAccessIterator _Last 
   ); 
template<class RandomAccessIterator, class BinaryPredicate> 
   void push_heap( 
      RandomAccessIterator _First,  
      RandomAccessIterator _Last,
      BinaryPredicate _Comp 
   );

参数

• _First
  处理第一元素位置的随机访问迭代器。堆。

• _Last
  寻址最终元素的随机访问迭代器位置一个将要转换的范围为堆。

• _Comp
  用户定义的谓词函数对象定义一个元素小于另一个。 二进制谓词采用两个参数，并且在满足时返回 true，在未满足时返回 false。

备注

必须先为现有元素推入堆的末尾然后使用算法将此元素添加到现有的堆。

堆具有两个属性：

• 第一个元素。始终最大。

• 元素在对数时间可能添加或删除。

堆为一个极好的方式实现优先级别队列，并用于标准模板库 (STL) 容器 priority_queue 类适配器的实现。

引用的范围必须是有效的；所有指针必须 dereferenceable，然后在序列中的最后位置从开始来访问通过递增。

除新添加的元素的范围。结束必须为堆。

复杂是对数的，要求最*_Last - _First*记录 () 比较。

示例

// alg_push_heap.cpp
// compile with: /EHsc
#include <vector>
#include <algorithm>
#include <functional>
#include <iostream>

int main( ) {
   using namespace std;
   vector <int> v1, v2;
   vector <int>::iterator Iter1, Iter2;

   int i;
   for ( i = 1 ; i <= 9 ; i++ )
      v1.push_back( i );

   random_shuffle( v1.begin( ), v1.end( ) );

   cout << "Vector v1 is ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")." << endl;

   // Make v1 a heap with default less than ordering
   make_heap ( v1.begin( ), v1.end( ) );
   cout << "The heaped version of vector v1 is ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")." << endl;

   // Add an element to the heap
   v1.push_back( 10 );
   cout << "The heap v1 with 10 pushed back is ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")." << endl;

   push_heap( v1.begin( ), v1.end( ) );
   cout << "The reheaped v1 with 10 added is ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")." << endl << endl;

   // Make v1 a heap with greater than ordering
   make_heap ( v1.begin( ), v1.end( ), greater<int>( ) );
   cout << "The greater-than heaped version of v1 is\n ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")." << endl;

   v1.push_back(0);
   cout << "The greater-than heap v1 with 11 pushed back is\n ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")." << endl;

   push_heap( v1.begin( ), v1.end( ), greater<int>( ) );
   cout << "The greater than reheaped v1 with 11 added is\n ( " ;
   for ( Iter1 = v1.begin( ) ; Iter1 != v1.end( ) ; Iter1++ )
      cout << *Iter1 << " ";
   cout << ")." << endl;
}

示例输出

Vector v1 is ( 9 2 7 3 1 6 8 4 5 ).
The heaped version of vector v1 is ( 9 5 8 4 1 6 7 2 3 ).
The heap v1 with 10 pushed back is ( 9 5 8 4 1 6 7 2 3 10 ).
The reheaped v1 with 10 added is ( 10 9 8 4 5 6 7 2 3 1 ).

The greater-than heaped version of v1 is
 ( 1 2 6 3 5 8 7 4 10 9 ).
The greater-than heap v1 with 11 pushed back is
 ( 1 2 6 3 5 8 7 4 10 9 0 ).
The greater than reheaped v1 with 11 added is
 ( 0 1 6 3 2 8 7 4 10 9 5 ).

要求

标头： <算法>

命名空间: std

请参见

参考

heap

标准模板库