数据结构-堆 C与C++的实现

堆,是一种完全二叉树。而且在这颗树中,父节点必然大于(对于小顶堆为小于)子节点。

关于树的概念不了解可以看这里:http://www.cnblogs.com/HongYi-Liang/p/7231440.html

由于堆是一种完全二叉树,很适合保存为数组的形式。如下图示意的堆,红色数字为数组索引,黑色数字为数组的值,那么这个堆保存为数组的形式:heap={9,8,5,6,7,1,4,0,3,2};

值得注意的是,在堆中,若设父亲的索引为i,左儿子的索引刚好等于2i,而右儿子的索引等于2i+1。这个公式会大量地出现在下边的程序中。

关键概念:

大顶堆:树根元素为最大值往叶子递减,(父节点总是大于子节点)

小顶堆:树根元素为最小值往叶子递增,(父节点总是小于子节点)

 

下为一个大顶堆的示意图,父节点总是大于子节点

 

 

在下面的程序中,C将以大顶堆的形式编写,C++以小顶堆的形式编写。


 

C语言

程序源码:

本例子为大顶堆,包含4个文件(如下图)

MaxHeap.c

#include "MaxHeap.h"

bool MaxHeapConstructByBuffer(MaxHeap *heap,MAXHEAP_ELEM buff[],int length);
bool MaxHeapDesturct(MaxHeap *heap);
bool MaxHeap_getSize(MaxHeap *heap);
bool MaxHeap_isFull(MaxHeap *heap);
bool MaxHeap_isEmpty(MaxHeap *heap);
void MaxHeap_swap(MAXHEAP_ELEM *a,MAXHEAP_ELEM *b);
void MaxHeap_floating(MaxHeap *heap,int index);
void MaxHeap_sink(MaxHeap *heap, int index);
bool MaxHeap_push(MaxHeap *heap,MAXHEAP_ELEM data);
bool MaxHeap_push(MaxHeap *heap,MAXHEAP_ELEM data);
bool MaxHeap_pop(MaxHeap *heap,int index);
void MaxHeap_printfAll(MaxHeap *heap);

bool MaxHeapConstructByBuffer(MaxHeap *heap,MAXHEAP_ELEM buff[],int length)
{
    int i;
    if(NULL != heap->iDatas)
    {
        return false;
    }
    heap->iHeapCapacity=length;
    heap->iHeapSize=0;
    heap->iDatas = (MAXHEAP_ELEM*)malloc(sizeof(MAXHEAP_ELEM)*length);
    for(i=0;i<length;i++)
    {
        MaxHeap_push(heap,buff[i]);
    }
    return true;
}

bool MaxHeapDesturct(MaxHeap *heap)
{
    if(NULL == heap->iDatas)
    {
        return false;
    }
    free(heap->iDatas);
    return true;
}

bool MaxHeap_getSize(MaxHeap *heap)
{
    return heap->iHeapSize;
}

bool MaxHeap_isFull(MaxHeap *heap)
{
    if(heap->iHeapCapacity == heap->iHeapSize)
    {
        return true;
    }
    return false;
}

bool MaxHeap_isEmpty(MaxHeap *heap)
{
    if(0 == heap->iHeapSize)
    {
        return true;
    }
    return false;
}

void MaxHeap_swap(MAXHEAP_ELEM *a,MAXHEAP_ELEM *b)
{
    MAXHEAP_ELEM temp;
    temp=*a;
    *a=*b;
    *b=temp;
}

void MaxHeap_floating(MaxHeap *heap,int index)
{
    int i;
    for(i=index;i>0;i=(int)(i*0.5))
    {
        if(heap->iDatas[i-1] > heap->iDatas[(int)(i*0.5-1)] )
        {
            MaxHeap_swap(&heap->iDatas[i-1],&heap->iDatas[(int)(i*0.5-1)]);
        }
        else 
        {
            break;
        }
    }    
}


void MaxHeap_sink(MaxHeap *heap, int index)
{
    int i=index;

    while(i*2<=heap->iHeapSize)
    {
        if(heap->iDatas[i-1] < heap->iDatas[i*2-1])//it compare to left child
        {
            MaxHeap_swap(&heap->iDatas[i-1],&heap->iDatas[i*2-1]);
            if(i*2+1<=heap->iHeapSize && heap->iDatas[i-1] < heap->iDatas[i*2])//it compare to right child
            {
                MaxHeap_swap(&heap->iDatas[i-1],&heap->iDatas[i*2]);            
            }
            /*index*/
            i=i*2;
        }
        else if(i*2+1<=heap->iHeapSize && heap->iDatas[i-1] < heap->iDatas[i*2])//it compare to right child
        {
            MaxHeap_swap(&heap->iDatas[i-1],&heap->iDatas[i*2]);
            i=i*2+1;
        }
        else
        {
            break;
        }
    }    
}

bool MaxHeap_push(MaxHeap *heap,MAXHEAP_ELEM data)
{
    if( MaxHeap_isFull(heap))
        return false;
    heap->iDatas[heap->iHeapSize]=data;
    heap->iHeapSize++;
    MaxHeap_floating(heap,heap->iHeapSize);

    return true;
}

bool MaxHeap_pop(MaxHeap *heap,int index)
{
    if(MaxHeap_isEmpty(heap))
        return false;
    heap->iDatas[index]=heap->iDatas[heap->iHeapSize-1];
    heap->iHeapSize--;
    MaxHeap_sink(heap,index+1);

    return true;
}

void MaxHeap_printfAll(MaxHeap *heap)
{
    int i;
    printf("heap:");
    for( i=0;i<heap->iHeapSize;i++)
    {
        printf("%d ",heap->iDatas[i]);
    }
    printf("\r\n");
}
View Code

MaxHeap.h

#ifndef __MAXHEAP_H
#define __MAXHEAP_H

#include <stdlib.h>
#include <stdio.h>
#include "Mystdbool.h"

typedef int MAXHEAP_ELEM;
typedef struct 
{
    int iHeapCapacity;
    int iHeapSize;
    MAXHEAP_ELEM *iDatas;
}MaxHeap;

bool MaxHeapConstructByBuffer(MaxHeap *heap,MAXHEAP_ELEM buff[],int length);
bool MaxHeapDesturct(MaxHeap *heap);
bool MaxHeap_getSize(MaxHeap *heap);
bool MaxHeap_isFull(MaxHeap *heap);
bool MaxHeap_isEmpty(MaxHeap *heap);
void MaxHeap_swap(MAXHEAP_ELEM *a,MAXHEAP_ELEM *b);
void MaxHeap_floating(MaxHeap *heap,int index);
void MaxHeap_sink(MaxHeap *heap, int index);
bool MaxHeap_push(MaxHeap *heap,MAXHEAP_ELEM data);
bool MaxHeap_push(MaxHeap *heap,MAXHEAP_ELEM data);
bool MaxHeap_pop(MaxHeap *heap,int index);
void MaxHeap_printfAll(MaxHeap *heap);

#endif
View Code

Mystdbool.h(仅用于声明布尔类)

#ifndef _MYSTDBOOL_H
#define _MYSTDBOOL_H

typedef enum Bool
{
    false=0,
    true,
}bool;




#endif
View Code

main.c

#include "MaxHeap.h"



int main()
{
    /*int buffer[10]={9,8,7,6,5,4,3,2,1,0};*/
    int buffer[10]={0,1,2,3,4,5,6,7,8,9};
    MaxHeap heap={0};
    MaxHeapConstructByBuffer(&heap,buffer,10);
    MaxHeap_printfAll(&heap);
    MaxHeap_pop(&heap,0);
    MaxHeap_printfAll(&heap);
    MaxHeap_pop(&heap,0);
    MaxHeap_printfAll(&heap);
    system("pause");
    return 0;
}
View Code

运行结果:

源码详解:

上浮:floating(int index) 

 

  1. 将堆第index个元素与它的父亲比较,若小于它的父亲,则与它父亲交换数值。
  2. 上述过程如果发生,则把它继续上浮。
void MaxHeap_floating(MaxHeap *heap,int index)
{
    int i;
    for(i=index;i>0;i=(int)(i*0.5))
    {
        if(heap->iDatas[i-1] > heap->iDatas[(int)(i*0.5-1)] )
        {
            MaxHeap_swap(&heap->iDatas[i-1],&heap->iDatas[(int)(i*0.5-1)]);
        }
        else 
        {
            break;
        }
    }    
}

 

添加元素:push(T data)

  1. 把元素添加到堆的最后。
  2. 并使用上浮方法把堆的最后一个元素上浮。
bool MaxHeap_push(MaxHeap *heap,MAXHEAP_ELEM data)
{
    if( MaxHeap_isFull(heap))
        return false;
    heap->iDatas[heap->iHeapSize]=data;
    heap->iHeapSize++;
    MaxHeap_floating(heap,heap->iHeapSize);

    return true;
}

 

构建堆:MaxHeapConstructByBuffer()

  1. 用malloc为数据申请空间。
  2. 一个一个地将buff中的数据push()到堆中。
bool MaxHeapConstructByBuffer(MaxHeap *heap,MAXHEAP_ELEM buff[],int length)
{
    int i;
    if(NULL != heap->iDatas)
    {
        return false;
    }
    heap->iHeapCapacity=length;
    heap->iHeapSize=0;
    heap->iDatas = (MAXHEAP_ELEM*)malloc(sizeof(MAXHEAP_ELEM)*length);
    for(i=0;i<length;i++)
    {
        MaxHeap_push(heap,buff[i]);
    }
    return true;
}

下沉:

  1. 从根开始,用父节点与左子节点比较。若父节点大于左子,则交换它们的值
  2. 用父节点与右子节点比较。若父节点大于右子,则交换它们的值。
  3. 若上述情况发生了,则继续下沉,直到无法下沉为止。
void MaxHeap_sink(MaxHeap *heap, int index)
{
    int i=index;

    while(i*2<=heap->iHeapSize)
    {
        if(heap->iDatas[i-1] < heap->iDatas[i*2-1])//it compare to left child
        {
            MaxHeap_swap(&heap->iDatas[i-1],&heap->iDatas[i*2-1]);
            if(i*2+1<=heap->iHeapSize && heap->iDatas[i-1] < heap->iDatas[i*2])//it compare to right child
            {
                MaxHeap_swap(&heap->iDatas[i-1],&heap->iDatas[i*2]);            
            }
            /*index*/
            i=i*2;
        }
        else if(i*2+1<=heap->iHeapSize && heap->iDatas[i-1] < heap->iDatas[i*2])//it compare to right child
        {
            MaxHeap_swap(&heap->iDatas[i-1],&heap->iDatas[i*2]);
            i=i*2+1;
        }
        else
        {
            break;
        }
    }    
}

删除元素:pop(int index)

  1. 把堆的第index个元素删除,并把堆的最后一个元素放到index处。
  2. 把堆的第index个元素下沉
bool MaxHeap_pop(MaxHeap *heap,int index)
{
    if(MaxHeap_isEmpty(heap))
        return false;
    heap->iDatas[index]=heap->iDatas[heap->iHeapSize-1];
    heap->iHeapSize--;
    MaxHeap_sink(heap,index+1);

    return true;
}

 


 

C++

程序源码:

本例子为小顶堆,包含2个文件(如下图)

MyMinHeap.h:

此文件中为小顶堆的类模板。

#ifndef __MYMINHEAP_H
#define __MYMINHEAP_H
#include <iostream>
#include <vector>


using namespace std;


template <typename T>
class MyMinHeap
{
public:
    MyMinHeap(T buff[],int length);
    MyMinHeap(int capacity);
    virtual ~MyMinHeap();
    int getSize();
    bool isFull();
    bool isEmpty();
    void swap(vector<T> &vec,int i,int j);
    void floating(int index);
    void sink(int index);
    bool push(T data);
    bool pop(int index);
    //transval
    void printfAll();
private:
    int m_iHeapCapacity;
    int m_iHeapSize;
    vector<T> m_vecData;
};


template <typename T>
MyMinHeap<T>::MyMinHeap(T buff[],int length)
{
    m_iHeapCapacity=length;
    m_iHeapSize=0;
    m_vecData.resize(length);
    for(int i=0;i<length;i++)
    {
        push(buff[i]);
    }
}

template <typename T>
MyMinHeap<T>::    MyMinHeap(int capacity)
{
    m_iHeapCapacity=capacity;
    m_iHeapSize=0;
    m_vecData.resize(capacity);
}

template <typename T>
MyMinHeap<T>::~MyMinHeap()
{

}

template <typename T>
int MyMinHeap<T>::getSize()
{
    return m_iHeapSize;
}

template <typename T>
bool MyMinHeap<T>::isFull()
{
    if(m_iHeapSize>=m_iHeapCapacity)
    {
        return true;
    }
    return false;
}
template <typename T>
bool MyMinHeap<T>::isEmpty()
{
    if(m_iHeapSize==0)
        return true;
    return false;
}

template <typename T>
void MyMinHeap<T>::swap(vector<T> &vec,int i,int j)
{
    T temp = vec[i];
    vec[i]=vec[j];
    vec[j]=temp;
}

template <typename T>
void MyMinHeap<T>::floating(int index)
{
    T temp;
    for(int i=index;i>0;i*=0.5)
    {
        if(m_vecData[i-1]<m_vecData[i*0.5-1] )
        {
            swap(m_vecData,i-1,i*0.5-1);
        }
        else 
        {
            break;
        }
    }    
}


template <typename T>
void MyMinHeap<T>::sink(int index)
{
    int i=index;

    while(i*2<=m_iHeapSize)
    {
        if(m_vecData[i-1]>m_vecData[i*2-1])//it compare to left child
        {
            swap(m_vecData,i-1,i*2-1);
            if(i*2+1<=m_iHeapSize && m_vecData[i-1]>m_vecData[i*2])//it compare to right child
            {
                swap(m_vecData,i-1,i*2);            
            }
            /*index*/
            i=i*2;
        }
        else if(i*2+1<=m_iHeapSize && m_vecData[i-1]>m_vecData[i*2])//it compare to right child
        {
            swap(m_vecData,i-1,i*2);
            i=i*2+1;
        }
        else
        {
            break;
        }
    }
}

template <typename T>
bool MyMinHeap<T>::push(T data)
{
    if(isFull())
        return false;
    m_vecData[m_iHeapSize]=data;
    m_iHeapSize++;
    floating(m_iHeapSize);

    return true;
}

template <typename T>
bool MyMinHeap<T>::pop(int index)
{
    if(isEmpty())
        return false;
    m_vecData[index]=m_vecData[m_iHeapSize-1];
    m_iHeapSize--;
    sink(index+1);

    return true;
}

template <typename T>
void MyMinHeap<T>::printfAll()
{
    cout<<"heap:";
    for(int i=0;i<m_iHeapSize;i++)
    {
        cout<<m_vecData[i]<<" ";
    }
    cout<<endl<<endl;
}


#endif
View Code

 

main.h:

主程序用于测试运行。

#include <iostream>
#include "MyMinHeap.h"
using namespace std;


int main()
{
    int buffer[10]={9,8,7,6,5,4,3,2,1,0};
    MyMinHeap<int> heap(buffer,10);
    heap.printfAll();
    heap.pop(1);
    heap.printfAll();
    heap.push(1);
    heap.printfAll();
    system("pause");
    return 0;
}
View Code

 

运行结果:

 

 

源码详解:

上浮:floating(int index)

  1. 将堆第index个元素与它的父亲比较,若小于它的父亲,则与它父亲交换数值。
  2. 上述过程如果发生,则把它继续上浮。
template <typename T>
void MyMinHeap<T>::floating(int index)
{
    T temp;
    for(int i=index;i>0;i*=0.5)
    {
        if(m_vecData[i-1]<m_vecData[i*0.5-1] )
        {
            swap(m_vecData,i-1,i*0.5-1);
        }
        else 
        {
            break;
        }
    }    
}

 

添加元素:push(T data)

  1. 把元素添加到堆的最后。
  2. 并使用上浮方法把堆的最后一个元素上浮。
template <typename T>
bool MyMinHeap<T>::push(T data)
{
    if(isFull())
        return false;
    m_vecData[m_iHeapSize]=data;
    m_iHeapSize++;
    floating(m_iHeapSize);

    return true;
}

 

构造函数:使用数组构建堆:

连续使用push()把buff中所有元素一个一个地加入堆中。

template <typename T>
MyMinHeap<T>::MyMinHeap(T buff[],int length)
{
    m_iHeapCapacity=length;
    m_iHeapSize=0;
    m_vecData.resize(length);
    for(int i=0;i<length;i++)
    {
        push(buff[i]);
    }
}

 

下沉:

  1. 从根开始,用父节点与左子节点比较。若父节点大于左子,则交换它们的值
  2. 用父节点与右子节点比较。若父节点大于右子,则交换它们的值。
  3. 若上述情况发生了,则继续下沉,直到无法下沉为止。
template <typename T>
void MyMinHeap<T>::sink(int index)
{
    int i=index;

    while(i*2<=m_iHeapSize)
    {
        if(m_vecData[i-1]>m_vecData[i*2-1])//it compare to left child
        {
            swap(m_vecData,i-1,i*2-1);
            if(i*2+1<=m_iHeapSize && m_vecData[i-1]>m_vecData[i*2])//it compare to right child
            {
                swap(m_vecData,i-1,i*2);            
            }
            /*index*/
            i=i*2;
        }
        else if(i*2+1<=m_iHeapSize && m_vecData[i-1]>m_vecData[i*2])//it compare to right child
        {
            swap(m_vecData,i-1,i*2);
            i=i*2+1;
        }
        else
        {
            break;
        }
    }
}

 

删除元素:pop(int index)

  1. 把堆的第index个元素删除,并把堆的最后一个元素放到index处。
  2. 把堆的第index个元素下沉
template <typename T>
bool MyMinHeap<T>::pop(int index)
{
    if(isEmpty())
        return false;
    m_vecData[index]=m_vecData[m_iHeapSize-1];
    m_iHeapSize--;
    sink(index+1);

    return true;
}

 


 

 

 

posted @ 2017-11-17 21:45  HongYi_Liang  阅读(4729)  评论(0编辑  收藏  举报