-
Notifications
You must be signed in to change notification settings - Fork 0
/
HeapSort.java
51 lines (45 loc) · 1.22 KB
/
HeapSort.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
public class HeapSort {
static void heapify(int a[], int n , int i){
int largest = i;
int left = 2*i+1;
int right = 2*i+2;
if(left<n && a[left]>a[largest]){
largest = left;
}
if(right<n && a[right]>a[largest]){
largest = right;
}
if(largest != i){
int temp = a[i];
a[i] = a[largest];
a[largest] = temp;
heapify(a, n, largest);
}
}
static void heapsort(int a[], int n){
for(int i =n/2 -1 ; i>=0;i--){
heapify(a, n, i);
}
for (int i = n-1; i >=0; i--) {
int temp = a[0];
a[0] = a[i];
a[i] = temp;
heapify(a, i, 0);
}
}
static void printElements(int a[], int n){
for (int i = 0; i < n; i++) {
System.out.print(a[i]+" ");
}
System.out.println();
}
public static void main(String[] args) {
int a[] = {45,7,20,40,25,23,-1};
int n = a.length;
System.out.println("BEFORE HEAP SORT : ");
printElements(a, n);
heapsort(a, n);
System.out.println("AFTER HEAP SORT : ");
printElements(a, n);
}
}