FilesExpand file tree

 master

/

MergeSort.java

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

92 lines (79 loc) · 2.34 KB

 master

/

MergeSort.java

Copy path

Top

File metadata and controls

• Code
• Blame

92 lines (79 loc) · 2.34 KB

Raw

Copy raw file

Download raw file

Open symbols panel

Edit and raw actions

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

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

package Sorts;

import static Sorts.SortUtils.print;

/**

* This method implements the Generic Merge Sort

*

* @author Varun Upadhyay (https://github.com/varunu28)

* @author Podshivalov Nikita (https://github.com/nikitap492)

* @see SortAlgorithm

*/

class MergeSort implements SortAlgorithm {

/**

* This method implements the Generic Merge Sort

*

* @param unsorted the array which should be sorted

* @param <T> Comparable class

* @return sorted array

*/

@Override

public <T extends Comparable<T>> T[] sort(T[] unsorted) {

doSort(unsorted, 0, unsorted.length - 1);

return unsorted;

}

/**

* @param arr The array to be sorted

* @param left The first index of the array

* @param right The last index of the array Recursively sorts the array in increasing order

*/

private static <T extends Comparable<T>> void doSort(T[] arr, int left, int right) {

if (left < right) {

int mid = left + (right - left) / 2;

doSort(arr, left, mid);

doSort(arr, mid + 1, right);

merge(arr, left, mid, right);

}

}

/**

* This method implements the merge step of the merge sort

*

* @param arr The array to be sorted

* @param left The first index of the array

* @param mid The middle index of the array

* @param right The last index of the array merges two parts of an array in increasing order

*/

private static <T extends Comparable<T>> void merge(T[] arr, int left, int mid, int right) {

int length = right - left + 1;

T[] temp = (T[]) new Comparable[length];

int i = left;

int j = mid + 1;

int k = 0;

while (i <= mid && j <= right) {

if (arr[i].compareTo(arr[j]) <= 0) {

temp[k++] = arr[i++];

} else {

temp[k++] = arr[j++];

}

}

while (i <= mid) {

temp[k++] = arr[i++];

}

while (j <= right) {

temp[k++] = arr[j++];

}

System.arraycopy(temp, 0, arr, left, length);

}

// Driver program

public static void main(String[] args) {

// Integer Input

Integer[] arr = {4, 23, 6, 78, 1, 54, 231, 9, 12};

MergeSort mergeSort = new MergeSort();

mergeSort.sort(arr);

// Output => 1 4 6 9 12 23 54 78 231

print(arr);

// String Inpu

String[] stringArray = {"c", "a", "e", "b", "d"};

mergeSort.sort(stringArray);

// Output => a b c d e

print(stringArray);

}

}