堆排序

#include <iostream>#include <ctime>#include <limits>using namespace std;void max_heapify(int *a,int i,int heap_size)//维护最大堆{while (i<=heap_size/2){int left=2*i+1,right=2*i+2;int largest=i;if(left<=heap_size && a[left]>a[i])largest=left;if(right<=heap_size && a[right]>a[largest])largest=right;if(largest != i){int tmp=a[i];a[i]=a[largest];a[largest]=tmp;i=largest;       //尾递归}else//递归结束break;}}void build_max_heapify(int *a,int heap_size)//建堆{for(int i=heap_size/2;i>=0;--i){max_heapify(a,i,heap_size);}}void heap_sort(int *a,int heap_size)//堆排序{build_max_heapify(a,heap_size);//建堆int tmp;for(int i=heap_size;i>0;--i){tmp=a[i];//值交换a[i]=a[0];a[0]=tmp;--heap_size;max_heapify(a,0,heap_size);//堆维护}}int heap_extract_max(int *a,int heap_size){if(heap_size<0)cout<<"heap underflow";int max=a[0];a[0]=a[heap_size];--heap_size;max_heapify(a,0,heap_size);return max;}void heap_increase_key(int *a,int index,int key)//增加堆的某个元素的值{if(a[index]>key)cout<<"new key smaller than current key";a[index]=key;while ((index>=0)&&(key>a[(index-1)/2])){//临时变量交换法/*int tmp=a[(index-1)/2];a[(index-1)/2]=a[index];a[index]=tmp;*///insertion_sort变量赋值法a[index]=a[(index-1)/2];index=(index-1)/2;}a[index]=key;//insertion_sort变量赋值法}void heap_delete(int *a,int i,int heap_size){if(i<0)cout<<"heap underflow";if(i>heap_size)cout<<"heap overflow";a[i]=a[heap_size];--heap_size;//元素个数减少一个if(a[i]>a[(i-1)/2]){//如果大于父亲节点heap_increase_key(a,i,a[i]);}else{max_heapify(a,i,heap_size);}}int main(){srand(time(NULL));int count;while ((count=rand()%101)<10);count=10;int a[10]={16,14,10,8,7,9,3,2,4,1};/*int *a=new int[count];for(int i=0;i<count;++i){a[i]=rand()%101-50;cout<<a[i]<<" ";}cout<<endl;*//*heap_sort(a,count-1);for(int i=0;i<count;++i){cout<<a[i]<<" ";}cout<<endl;*/build_max_heapify(a,count-1);for(int i=0;i<count;++i){cout<<a[i]<<" ";}cout<<endl;/*int ex_max=heap_extract_max(a,count-1);cout<<ex_max<<endl;for(int i=0;i<count-1;++i){cout<<a[i]<<" ";}cout<<endl;*/heap_increase_key(a,8,15);for(int i=0;i<count;++i){cout<<a[i]<<" ";}cout<<endl;heap_delete(a,2,count-1);for(int i=0;i<count-1;++i){cout<<a[i]<<" ";}cout<<endl;//int rnd=rand()%101-50;//delete[]a;}