public class HeapSort {
public static void heapSort(DataWraper[] data){
System.out.println("開始排序");
int arrayLength=data.length;
//循環(huán)建堆
for(int i=0;i<arrayLength-1;i++){
//建堆
buildMaxHeap(data,arrayLength-1-i);
//交換堆頂和最后一個(gè)元素
swap(data,0,arrayLength-1-i);
System.out.println(Arrays.toString(data));
}
}
private static void swap(DataWraper[] data, int i, int j) {
// TODO Auto-generated method stub
DataWraper tmp=data[i];
data[i]=data[j];
data[j]=tmp;
}
//對data數(shù)組從0到lastIndex建大頂堆
private static void buildMaxHeap(DataWraper[] data, int lastIndex) {
// TODO Auto-generated method stub
//從lastIndex處節(jié)點(diǎn)(最后一個(gè)節(jié)點(diǎn))的父節(jié)點(diǎn)開始
for(int i=(lastIndex-1)/2;i>=0;i--){
//k保存正在判斷的節(jié)點(diǎn)
int k=i;
//如果當(dāng)前k節(jié)點(diǎn)的子節(jié)點(diǎn)存在
while(k*2+1<=lastIndex){
//k節(jié)點(diǎn)的左子節(jié)點(diǎn)的索引
int biggerIndex=2*k+1;
//如果biggerIndex小于lastIndex,即biggerIndex+1代表的k節(jié)點(diǎn)的右子節(jié)點(diǎn)存在
if(biggerIndex<lastIndex){
//若果右子節(jié)點(diǎn)的值較大
if(data[biggerIndex].compareTo(data[biggerIndex+1])<0){
//biggerIndex總是記錄較大子節(jié)點(diǎn)的索引
biggerIndex++;
}
}
//如果k節(jié)點(diǎn)的值小于其較大的子節(jié)點(diǎn)的值
if(data[k].compareTo(data[biggerIndex])<0){
//交換他們
swap(data,k,biggerIndex);
//將biggerIndex賦予k,開始while循環(huán)的下一次循環(huán),重新保證k節(jié)點(diǎn)的值大于其左右子節(jié)點(diǎn)的值
k=biggerIndex;
}else{
break;
}
}
}
}
public static void main(String[] args) {
// TODO Auto-generated method stub
DataWraper [] data={
new DataWraper(21, ""),
new DataWraper(30, ""),
new DataWraper(49, ""),
new DataWraper(30, "*"),
new DataWraper(16, ""),
new DataWraper(9, ""),
};
System.out.println("排序之前:/n"+Arrays.toString(data));
heapSort(data);
System.out.println("排序之后:/n"+Arrays.toString(data));
}
}
結(jié)果:
排序之前:
[21, 30, 49, 30*, 16, 9]
開始排序
[9, 30, 21, 30*, 16, 49]
[16, 30*, 21, 9, 30, 49]
[9, 16, 21, 30*, 30, 49]
[9, 16, 21, 30*, 30, 49]
[9, 16, 21, 30*, 30, 49]
排序之后:
[9, 16, 21, 30*, 30, 49]
新聞熱點(diǎn)
疑難解答
圖片精選