堆排序的练习

//HeapSorter.h

#pragma once

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


class HeapSorter
{
public:
HeapSorter(int nVecLength);
~HeapSorter(void);


protected:
HeapSorter()
{
m_pVect = NULL;
m_nVecLens = 0;
}


public:
void RandomValueVector();
void OutputVector();


void MinHeapSortToDescendArray();  //最小堆的降序排序




protected:
void MinHeapFixup(int *pArr, int i);  //数组i元素更新到小堆的插入操作
//调整i节点的位置更新至正确的小堆：小堆的i节点下沉
void MinHeapFixdown(int *pArr, int i, int n);


void MakeMinHeap(int *pArr, int n);   //从乱序数组建立最小堆




protected:
int  *m_pVect;
int  m_nVecLens;

};

//HeapSorter.cpp

#include "HeapSorter.h"


#include <time.h>
#include <assert.h>




HeapSorter::HeapSorter(int nVecLength)
{
m_nVecLens = nVecLength;
if(m_nVecLens > 0)
{
m_pVect = new int[m_nVecLens];
}
else
m_pVect = NULL;


srand(time(NULL));
}




HeapSorter::~HeapSorter(void)
{
if(m_pVect)
{
delete []m_pVect;
m_pVect = NULL;
}
}


void HeapSorter::RandomValueVector()
{
int  *ptr=m_pVect;


for(int i=0; i < m_nVecLens; i++)
{
*ptr++ = rand();
}
}


void HeapSorter::MinHeapFixup(int *pArr, int i)
{
assert(pArr && i > 0);


int j, temp;


temp = pArr[i];
j = (i -1) / 2;  //父节点


while(j >= 0 && i > 0)
{
if(pArr[j] <= temp)
break;


pArr[i] = pArr[j];


i = j;
j = (i -1) / 2;  //父节点
}


pArr[i] = temp;
}


void HeapSorter::MinHeapFixdown(int *pArr, int i, int n)
{
assert(pArr && i >= 0 && n > 0); 


int j, temp;


temp = pArr[i];
j = 2*i + 1;  //第一个子节点


while(j < n)
{
if(j + 1 < n && pArr[j+1] < pArr[j])
j++;


if(pArr[j] >= temp)
break;


pArr[i] = pArr[j];


i = j;
j = 2*i + 1;  //第一个子节点
}
pArr[i] = temp;
}


void HeapSorter::MakeMinHeap(int *pArr, int n)
{
assert(pArr && n > 0);


for(int i = n / 2 - 1; i >= 0; i--)
{
MinHeapFixdown(pArr, i, n);
}
}


void HeapSorter::MinHeapSortToDescendArray()
{
assert(m_pVect && m_nVecLens > 0);


MakeMinHeap(m_pVect, m_nVecLens);


int temp = 0;
for(int i = m_nVecLens - 1; i > 0; i--)
{
temp = m_pVect[i];
m_pVect[i] = m_pVect[0];
m_pVect[0] = temp;


MinHeapFixdown(m_pVect, 0, i);
}
}


void HeapSorter::OutputVector()
{
int lineNum = 20;
for(int i = 0; i < m_nVecLens; i++)
{
printf("%5d", m_pVect[i]);
if(i % lineNum == lineNum - 1)
{
printf("\n");
}
else
printf("\t");
}


printf("\n\n");
}

//main.cpp

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


#include "HeapSorter.h"




int main()
{
HeapSorter sorter(100);


sorter.RandomValueVector();
sorter.OutputVector();
sorter.MinHeapSortToDescendArray();
sorter.OutputVector();


sorter.RandomValueVector();
sorter.OutputVector();
sorter.MinHeapSortToDescendArray();
sorter.OutputVector();


printf("press any key to exit:");
getchar();
}