Find TopK value, by small heap

This is the code to get top k values from a input.

1. /*
2.  * Get the Top Largest K values from small heap
3.  */
4. public class TopK {
6.     public static void main(String[] args) {
7.         int[] array = {5, 13,10,12,15,11, 8,23, 40, 16, 83, 23, 31, 73, 59, 25, 75};
8.         findTopK(array, 5);
9.     }
11.     public static void findTopK(int[] array, int k){
12.         int[] heap = new int[k+1];
13.         heap[0] = k;     //use heap[0] to record the length of heap
14.         for(int i=0;i
15.             heapPut(heap, array[i]);
16.         }
17.         printArray(heap);
18.     }
20.     /*
21.      * Small heap, put value in heap
22.      */
23.     public static void heapPut(int[] heap, int value){
24.         if(heap==null){
25.             return;
26.         }
27.         if(value>heap[1]){
28.             heap[1] = value;
29.             heapAdjust(heap, 1);
30.         }
31.     }
34.     /*
35.      * Small heap, put value in heap
36.      */
37.     public static void heapAdjust(int[] heap, int pos){
38.         if(heap==null||pos*2>heap[0]){    //heap is empty, or the position is not correct
39.             return;
40.         }
41.         if(heap[pos]<=heap[pos*2]&&(heap[0]==pos*2||heap[pos]<=heap[pos*2+1])){
42.         //the heap[pos] is already smallest
43.      //heap[0]==pos*2 is to check if pos has right child. If it doesn’t has right child, then don’t compare with right child.
44.             return;
45.         }
46.         int minPos = (heap[0]==pos*2)?pos*2:heap[pos*2]//heap[pos] is not the smallest, get the min pos
48.         arrayExchange(heap, pos, minPos);
49.         heapAdjust(heap, minPos);
50.     }
53.     /*
54.      * Exchange pos1 and pos2 in array[]
55.      */
56.     public static void arrayExchange(int[] array, int pos1, int pos2){
57.         if(array==null||pos1>array.length-1||pos2>array.length-1){
58.             return;
59.         }
60.         int tmp = array[pos1];    array[pos1] = array[pos2]; array[pos2] = tmp;
61.         return;
62.     }
64.     public static void printArray(int[] array){
65.         if(array==null){
66.             return;
67.         }
68.         for(int i=1;i
69.             System.out.print(array[i]+” “);
70.         }
71.         System.out.println();
72.     }
73. }