forked from diwu001/Algorithm
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Heap_Sort.java
62 lines (55 loc) · 1.37 KB
/
Heap_Sort.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
package heap_sort;
import java.util.Arrays;
public class Heap_Sort {
protected double A[];
protected int heapsize;
//constructors
public Heap_Sort(){}
public Heap_Sort(double A[]){
buildMaxHeap(A);
}
protected int parent(int i) {return (i - 1) / 2;}
protected int left(int i) {return 2 * i + 1;}
protected int right(int i) {return 2 * i + 2;}
protected void maxHeapify(int i){
int l = left(i);
int r = right(i);
int largest = i;
if (l <= heapsize-1 && A[l] > A[i])
largest = l;
if (r <= heapsize-1 && A[r] > A[largest])
largest = r;
if (largest != i) {
double temp = A[i];
// swap
A[i] = A[largest];
A[largest] = temp;
maxHeapify(largest);
}
}
public void buildMaxHeap(double [] A){
this.A = A;
heapsize = A.length;
for (int i = parent(heapsize-1); i >= 0; i--)
maxHeapify(i);
}
public void sort(double [] A){
buildMaxHeap(A);
int step = 1;
for (int i = A.length-1; i > 0; i--) {
double temp = A[i];
A[i] = A[0];
A[0] = temp;
heapsize--;
System.out.println((step++) + Arrays.toString(A));
maxHeapify(0);
}
}
public static void main(String[] args) {
double [] A = {3, 7, 2, 11, 3, 4, 9, 2, 18, 0};
System.out.println(Arrays.toString(A));
Heap_Sort maxhp = new Heap_Sort();
maxhp.sort(A);
System.out.println(Arrays.toString(A));
}
}