Java Reference
In-Depth Information
66
// if left array is empty
67
if
(leftIndex == middle2)
68
// copy in rest of right array
69
while
(rightIndex <= right)
70
combined[combinedIndex++] = data[rightIndex++];
71
else
// right array is empty
72
// copy in rest of left array
73
while
(leftIndex <= middle1)
74
combined[combinedIndex++] = data[leftIndex++];
75
76
// copy values back into original array
77
for
(
int
i = left; i <= right; i++)
78
data[i] = combined[i];
79
80
// output merged array
81
System.out.printf(
" %s%n%n"
,
82
subarrayString(data, left, right));
83
}
// end method merge
84
85
// method to output certain values in array
86
private static
String subarrayString(
int
[] data,
int
low,
int
high)
87
{
88
StringBuilder temporary =
new
StringBuilder();
89
90
// output spaces for alignment
91
for
(
int
i =
0
; i < low; i++)
92
temporary.append(
" "
);
93
94
// output elements left in array
95
for
(
int
i = low; i <= high; i++)
96
temporary.append(
" "
+ data[i]);
97
98
return
temporary.toString();
99
}
100
101
public static void
main(String[] args)
102
{
103
SecureRandom generator =
new
SecureRandom();
104
105
int
[] data =
new
int
[
10
];
// create array
106
107
for
(
int
i =
0
; i < data.length; i++)
// populate array
108
data[i] =
10
+ generator.nextInt(
90
);
109
110
System.out.printf(
"Unsorted array:%n%s%n%n",
111
Arrays.toString(data));
// display array
112
113
114
System.out.printf(
"Sorted array:%n%s%n%n",
115
Arrays.toString(data));
// display array
116
}
117
}
// end class MergeSortTest
mergeSort(data);
// sort array
Fig. 19.6
|
Sorting an array with merge sort. (Part 3 of 5.)
