优先队列（缺）

#include <stdio.h>
typedef int ElementType;

struct HeapStruct;
typedef struct HeapStruct *PriorityQueue;

PriorityQueue Initialize( int MaxElements );
void Destroy( PriorityQueue H );
void MakeEmpty( PriorityQueue H );
void Insert( ElementType X, PriorityQueue H );
ElementType DeleteMin( PriorityQueue H );
ElementType FindMin( PriorityQueue H);
int IsEmpty( PriorityQueue H );
int IsFull( PriorityQueue H );

struct HeapStruct
{
    int Capacity;
    int Size;
    ElementType *Elements;
};


int main()
{
    return 0;
}

PriorityQueue
Initialize( int MaxElements)
{
    PriorityQueue H;

    if( MaxElements < MinPQSize )
        Error( "Priority queue size is too small");

    H = malloc( sizeof( struct HeapStruct ) );
    if( H == NULL )
        FatalError( "Out of space!!!");

    H->Elements = malloc( ( MaxElements + 1 )
                            * sizeof( ElementType) );

    if( H->Elements == NULL )
        FatalError( "Out of space!!!");

    H->Capacity = MaxElements;
    H->Size = 0;
    H->Elements[ 0 ] = MinData;

    return H;
}

/* H->Element [0] is a sentinel 哨兵*/
void 
Insert(ElementType X, PriorityQueue H)
{
    int i;

    if( IsFull( H ) )
    {
        Error("Priority queue is full");
        return;
    }

    for( i = ++H->Size; H->Elements[ i / 2] > X; i /=2 )
        H->Elements[ i ] = H->Elements[ i / 2];
    H->Elements[ i ] = X;
}

ElementType
DeleteMin( PriorityQueue H)
{
    int i, child;
    ElementType MinElement, LastElement;

    if( IsEmpty( H ))
    {
        Error( "Priority queue is empty ");
        return H->Elements[ 0 ];
    }
    MinElement = H->Elements[ 1 ];
    LastElement = H->Elements[ H->Size-- ];

    for( i = 1; i * 2 <= H->Size; i = Child)
    {
        /* Find smaller child*/
        Child = i * 2;
        if(Child != H->Size && H->Elements[ Child + 1 ]
                            < H->Capacity[ Child])
            Child++;

        if( LastElement > H->Elements[ Child ])
            H->Elements[ i ] = H->Elements[ Child ];
        else
            break;
    }
    H->Elements[ i ] = LastElement;
    return MinElement;
}