public class heap_Sort {
int a []={12,34,543,21,543,645,65,254767,54,7687,9808,234};
public heap_Sort(){
heapsort(a);
}
public void heapsort(int[] a){
int alengh=a.length;
for (int i=0;i<alengh;i++){
buildMaxHeap(a,alengh-1-i);
}
}
//
private void buildMaxHeap(int [] data,int lastindex){
for(int i=(lastindex-1)/2;i>=0;i--){
int k=i;
while(k*2+1<=lastindex){
int bigindex=2*k+1;
if(bigindex<lastindex){
if(data[bigindex]<data[bigindex+1]){
bigindex++;
}
}
if(data[k]<data[bigindex]){
swap(data,k,bigindex);
k=bigindex;
}else{break;}
}
}
}
//
private void swap(int [] data,int i,int j){
int tmp=data[i];
data[i]=data[j];
data[j]=tmp;
}
}
