归并排序（MergeSort） Java实现
归并排序的Java实现：
import java.util.Arrays;public class MergeSort { public static void sort(Comparable[] data, int p, int r) { /* * p = 0; r = 3; total 4; * q = (0 + 3) / 2; q = 1; * sort(0, 1); sort(2,3); * sort(p, q); sort(q + 1, r); */ if (p < r) { int q = (p + r) / 2; sort(data, p, q); sort(data, q + 1, r); merge(data, p, q, r); } } private static void merge(Comparable[] data, int p, int q, int r) { Comparable[] left = Arrays.copyOfRange(data, p, q + 1); Comparable[] right = Arrays.copyOfRange(data, q + 1, r + 1); int i = 0; int j = 0; int k = 0; while (k < r - p + 1) { if (i == left.length) { data[p + k] = right[j++]; } else if (j == right.length) { data[p + k] = left[i++]; } else if (left[i].compareTo(right[j]) < 0) { data[p + k] = left[i++]; } else { data[p + k] = right[j++]; } k++; } }}