小根堆的实现_by watson.long

最新推荐文章于 2024-06-28 01:29:51 发布

转载最新推荐文章于 2024-06-28 01:29:51 发布 · 105 阅读

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原文链接：http://www.cnblogs.com/watsonlong/archive/2011/03/25/1995023.html

本文介绍了一种小根堆的数据结构实现，并通过具体的代码示例展示了如何利用该数据结构进行堆排序。主要内容包括：小根堆的基本操作如创建、下沉、上浮、插入和删除元素等，以及如何使用这些操作完成对整型数组的排序。

小根堆的实现

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#include "stdio.h"
#include "stdlib.h"
#include "string.h"
/*minheap struct*/
typedef struct hnode{
int heap[100];
int currentsize;
}minheapnode,*minheap;

/*minheap*/
void creatheap(minheap *h,int a[], int n);
void siftdown(minheap *h,int i,int m);
void siftup(minheap *h,int start);
void insert(minheap *h,int x);
int remove(minheap *h);
void heapsort(minheap *h,int a[], int n);

void main(int argc,char *argv[])
{

int data[10]={9,1,2,4,6,10,23,5,3,56};
/*sort*/
minheap h;
h=(minheap)malloc(sizeof(minheapnode));
h->currentsize=0;
heapsort(&h,data,10);
}

/*heap sort*/
void heapsort(minheap *h,int a[], int n)
{
int i;
int temp;
/*creat heap*/
creatheap(h,a,n);
/*sort heap*/
for(i=(*h)->currentsize-1;i>0;i--)
{
temp=(*h)->heap[0];
(*h)->heap[0]=(*h)->heap[i];
(*h)->heap[i]=temp;
siftdown(h,0,i-1);
}
/*print sort heap*/
for(i=(*h)->currentsize-1;i>=0;i--)
{
printf("%d ",(*h)->heap[i]);
}
return;
}
/*creat minheap*/
void creatheap(minheap *h,int a[], int n)
{
int currentpos;
int i;
for(i=0;i<n;i++)
{
(*h)->heap[i]=a[i];
}
(*h)->currentsize=n;
currentpos=((*h)->currentsize-2)/2;
while(currentpos >=0)
{
siftdown(h,currentpos,(*h)->currentsize-1);
currentpos--;
}
}
/*siftdown function*/
void siftdown(minheap *h,int i,int m)
{
int j;
int temp=(*h)->heap[i];
for(j=2*i+1;j<=m;j=2*j+1)
{
if( (j<m) && ( (*h)->heap[j] > (*h)->heap[j+1] ) ) j++;
if(temp <= (*h)->heap[j]) break;
else
{
(*h)->heap[i]=(*h)->heap[j];
i=j;
}
}
(*h)->heap[i]=temp;
}
/*siftup function*/
void siftup(minheap *h,int start)
{
int temp,i,j;
temp=(*h)->heap[start];
j=start;
i=(j-1)/2;

while(j>0)
{
if((*h)->heap <= temp) break;
else
{
(*h)->heap[j] = (*h)->heap[i];
j=i;
i=(i-1)/2;
}
}

(*h)->heap[j]=temp;
}
/*insert handle*/
void insert(minheap *h,int x)
{
if((*h)->currentsize == 100) return;
(*h)->heap[(*h)->currentsize]=x;
siftup(h,(*h)->currentsize);
(*h)->currentsize++;
return;
}
/*remove handle*/
int remove(minheap *h)
{
int x=0;
if((*h)->currentsize==0) return;
x=(*h)->heap[0];
(*h)->heap[0]=(*h)->heap[(*h)->currentsize-1];
(*h)->currentsize--;
siftdown(h,0,(*h)->currentsize-1);
return x;
}

转载于:https://www.cnblogs.com/watsonlong/archive/2011/03/25/1995023.html