1 int heapmax(int arr[])
2 {
3     return arr[1];//返回堆顶
4 }

 1 int heap_extract_max(int arr[],int &heap_size)//去掉并返回arr中具有最大键字的元素
 2 {
 3     if(heap_size<1) //
 4     {
 5         cout<<"heap underflow"<<endl;
 6         return -1;
 7     }
 8     int max_=arr[1];
 9     arr[1]=arr[heap_size];
10     heap_size--;
11     max_heapify(arr,1,heap_size);
12     return max_;
13 }

int heap_increase_key(int arr[],int x,int k,int heap_size)//把元素x的关键字值增加到key，假设k的值不小于x原本关键字的值
{if(k<arr[x]){cout<<"new key is smaller than current key";}arr[x]=k;while(x>1&&arr[x/2]<arr[x])//插入值x的粑粑比崽值小，于是交换元素值
    {swap(arr[x/2],arr[x]);x=x/2;}
}

1 void max_heap_insert(int arr[],int k,int &heap_size)//把元素x值插入到集合中
2 {
3     heap_size++;
4     arr[heap_size]=-1;//通过增加一个关键字为负无穷的叶节点来扩展最大堆，这里用-1代替
5     heap_increase_key(arr,heap_size,k,heap_size);
6 }

  1 #include<iostream>
  2 #include<algorithm>
  3 #include<cstdlib>
  4 using namespace std;
  5 void max_heapify(int arr[],int i,int heap_size)//维护堆
  6 {
  7     int largest;
  8     int left=2*i;
  9     int right=2*i+1;
 10     if(left<=heap_size&&arr[left]>arr[i]) largest=left;
 11     else largest=i;
 12     if(right<=heap_size&&arr[right]>arr[largest])
 13         largest=right;
 14     if(largest!=i)
 15     {
 16         swap(arr[largest],arr[i]);
 17         max_heapify(arr,largest,heap_size);
 18     }
 19 }
 20 void build_max_heap(int arr[],int length)//建立堆
 21 {
 22     int heap_size=length;
 23     for(int i=length/2; i>=1; i--)
 24     {
 25         max_heapify(arr,i,heap_size);
 26     }
 27 }
 28 void heapsort(int arr[],int length)
 29 {
 30     int heap_size=length;
 31     build_max_heap(arr,length);
 32     for(int i=length; i>=2; i--)
 33     {
 34         swap(arr[1],arr[i]);
 35         heap_size--;
 36         max_heapify(arr,1,heap_size);
 37     }
 38 }
 39 int heapmax(int arr[])
 40 {
 41     return arr[1];//返回堆顶
 42 }
 43 int heap_extract_max(int arr[],int &heap_size)//去掉并返回arr中具有最大键字的元素
 44 {
 45     if(heap_size<1) //
 46     {
 47         cout<<"heap underflow"<<endl;
 48         return -1;
 49     }
 50     int max_=arr[1];
 51     arr[1]=arr[heap_size];
 52     heap_size--;
 53     max_heapify(arr,1,heap_size);
 54     return max_;
 55 }
 56 int heap_increase_key(int arr[],int x,int k,int heap_size)//把元素x的关键字值增加到key，假设k的值不小于x原本关键字的值
 57 {
 58     if(k<arr[x])
 59     {
 60         cout<<"new key is smaller than current key";
 61     }
 62     arr[x]=k;
 63     while(x>1&&arr[x/2]<arr[x])//插入值x的粑粑比崽值小，于是交换元素值
 64     {
 65         swap(arr[x/2],arr[x]);
 66         x=x/2;
 67     }
 68 }
 69 void max_heap_insert(int arr[],int k,int &heap_size)//把元素x值插入到集合中
 70 {
 71     heap_size++;
 72     arr[heap_size]=-1;//通过增加一个关键字为负无穷的叶节点来扩展最大堆，这里用-1代替
 73     heap_increase_key(arr,heap_size,k,heap_size);
 74 }
 75 void show(int arr[],int heap_size)
 76 {
 77     cout<<"show the heap:";
 78     for(int i=1; i<=heap_size; i++)
 79     {
 80         cout<<arr[i]<<" ";
 81     }
 82     cout<<endl;
 83 }
 84 int main()
 85 {
 86     int arr[]= {0,5,6,8,99,102,3,54,76,89,21};
 87     int heap_size=10;
 88     build_max_heap(arr,heap_size);//建堆
 89     int maxn=heapmax(arr);
 90     cout<<"the max data is:"<<maxn<<endl;
 91     maxn=heap_extract_max(arr,heap_size);
 92     cout<<"now the max data "<<maxn<<" was deleted."<<endl;
 93     show(arr,heap_size);
 94     heapsort(arr,heap_size);
 95     cout<<"after sort and";
 96     show(arr,heap_size);
 97     int i=6,key=80;
 98     heap_increase_key(arr,i,key,heap_size);//把堆中第i个元素的值改为key值。
 99     max_heap_insert(arr,100,heap_size);//插入新值100
100     show(arr,heap_size);
101     heapsort(arr,heap_size);
102     cout<<"after sort and";
103     show(arr,heap_size);
104     return 0;
105 }