堆排序

#include <iostream>
#include <fstream>
#include <vector>
#include <algorithm>
#include <string>
#include <cmath>
using namespace std;


int HeapSort(vector<int>& Array);
int BuildMaxHeap(vector<int>& Array);
int MaxHeapify(vector<int>& Array,vector<int>::iterator i,vector<int>::iterator EndIt,int length);


int main(){
ifstream infile("input.txt");
int Temp;
vector<int> Array;
while(infile>>Temp){
Array.push_back(Temp);
}
HeapSort(Array);
vector<int>::iterator it=Array.begin();
for(;it!=Array.end();it++){
cout<<*it<<endl;
}
}


int HeapSort(vector<int>& Array){
int Temp;
int length;
length=BuildMaxHeap(Array);
vector<int>::iterator It=Array.end()-1;
vector<int>::iterator EndIt=It;
for(;It>Array.begin();It--){
Temp=*It;
*It=*(Array.begin());
*(Array.begin())=Temp;
EndIt=EndIt-1;
MaxHeapify(Array,Array.begin(),EndIt,length);
}
return 0;
}




int BuildMaxHeap(vector<int>& Array){
vector<int>::iterator it=Array.begin();
vector<int>::iterator EndIt=Array.end()-1;
int Distance;
Distance=distance(Array.begin(),Array.end());
int i,sum=1,sum2=1,sum3;
for(i=1;i<100;i++){
sum=sum*2;
sum2=sum-1;
sum3=sum2; //计算出Array.length
if(sum2>=Distance){
break;
}
}
sum2=sum2/2-1; //减1是因为要满足advance的加法
advance(it,sum2);
cout<<*it;
for(;it>Array.begin();it--){
MaxHeapify(Array,it,EndIt,sum3);
}
MaxHeapify(Array,Array.begin(),EndIt,sum3);
return sum3;
}


int MaxHeapify(vector<int>& Array,vector<int>::iterator i,vector<int>::iterator EndIt,int length){
int Distance;
int Temp;
vector<int>::iterator Largest;
Distance=distance(Array.begin(),i);
Distance=Distance+1;
Distance=Distance*2;
if(Distance>length){
return 0;
}
vector<int>::iterator l=Array.begin();
Distance=Distance-1;
advance(l,Distance);
vector<int>::iterator r=l+1;
if((l<=EndIt)&&(*l>*i)){
Largest=l;
}
else{
Largest=i;
}
if((r<=EndIt)&&(*r>*Largest)){
Largest=r;
}
if(Largest!=i){
Temp=*Largest;
*Largest=*i;
*i=Temp;
MaxHeapify(Array,Largest,EndIt,length);
}
return 0;
}