Java Practice 8

Write a program for merge sort?

1. public class MergeSort {
2. private int[] array;
3. private int[] tempMergArr;
4. private int length;
5. public static void main(String a[]){
6. int[] inputArr = {45,23,11,89,77,98,4,28,65,43};
7. MergeSort mms = new MergeSort();
8. mms.sort(inputArr);
9. for(int i:inputArr){
10. System.out.print(i);
11. System.out.print(" ");
12. }
13. }
14. public void sort(int inputArr[]) 
15. {
16. this.array = inputArr;
17. this.length = inputArr.length;
18. this.tempMergArr = new int[length];
19. doMergeSort(0, length - 1);
20. }
21. private void doMergeSort(int lowerIndex, int higherIndex) {
22. 
    
23. if (lowerIndex < higherIndex) {
24. int middle = lowerIndex + (higherIndex - lowerIndex) / 2;
25. // Below step sorts the left side of the array
26. doMergeSort(lowerIndex, middle);
27. // Below step sorts the right side of the array
28. doMergeSort(middle + 1, higherIndex);
29. // Now merge both sides
30. mergeParts(lowerIndex, middle, higherIndex);
31. }
32. }
33. private void mergeParts(int lowerIndex, int middle, int higherIndex) 
34. {
35. for (int i = lowerIndex; i <= higherIndex; i++) {
36. tempMergArr[i] = array[i];
37. }
38. int i = lowerIndex;
39. int j = middle + 1;
40. int k = lowerIndex;
41. while (i <= middle && j <= higherIndex) {
42. if (tempMergArr[i] <= tempMergArr[j]) {
43. array[k] = tempMergArr[i];
44. i++;
45. } else {
46. array[k] = tempMergArr[j];
47. j++;
48. }
49. k++;
50. }
51. while (i <= middle) {
52. array[k] = tempMergArr[i];
53. k++;
54. i++;
55. }
56. 
    
57. }
58. }