FilesExpand file tree

 master

/

MergeSort.java

Copy path

Blame

More file actions

Blame

More file actions

Latest commit

 

History

History

History

106 lines (88 loc) · 2.75 KB

 master

/

MergeSort.java

Top

File metadata and controls

• Code
• Blame

106 lines (88 loc) · 2.75 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

93

94

95

96

97

98

99

100

101

102

103

104

105

106

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

@SuppressWarnings("unchecked")

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

T[] tmp = (T[]) new Comparable[unsorted.length];

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

return unsorted;

}

/**

*

* @param arr The array to be sorted

* @param temp The copy of the actual array

* @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, T[] temp, int left, int right) {

if (left < right) {

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

doSort(arr, temp, left, mid);

doSort(arr, temp,mid + 1, right);

merge(arr, temp, left, mid, right);

}

}

/**

* This method implements the merge step of the merge sort

*

* @param arr The array to be sorted

* @param temp The copy of the actual array

* @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, T[] temp, int left, int mid, int right) {

System.arraycopy(arr, left, temp, left, right - left + 1);

int i= left;

int j = mid + 1;

int k = left;

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

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

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

}

else {

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

}

}

while (i <= mid) {

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

}

while (j <= right) {

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

}

}

// 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);

}

}