我希望能够修改此代码,使其使用Knuth的H序列而不是这个序列。如果有人能帮忙,我将不胜感激。
public class ShellSort {
static int iterations = 0;
static void insert(double[] a, int h, int r, double v) {
int i = r - h;
while (i >= 0 && a[i] > v) {
a[i+h] = a[i]; i = i - h;
iterations ++;
}
a[i+h] = v;
}
static void version0(double[] a, int p, int q) {
int h;
h = 1;
for (int i = p + h; i < q; i++) {
insert(a, h, i, a[i]);
}
}
public static void main(String[] argv) {
int size = Integer.parseInt(argv[0]);
double a[] = new double[ size ];
for (int i = 0; i < a.length; i++) {
a[ i ] = Math.random();
System.out.println(i + " " + a[ i ]);
}
version0(a, 0, a.length);
for (int i = 0; i < a.length; i++) {
System.out.println(i + " " + a[ i ]);
}
System.out.println("Iterations "+ iterations);
}
}
对于序列1,2,4,8,16,我相信这可能是正确的?将version0类替换为:
static void version1(double[] a, int p, int q) {
int h;
for (h = 1; h <= a.length / 2; h = 2 * h)
/* nothing */ ;
for ( ; h > 0; h = h / 2) {
for (int i = p + h; i < q; i++) {
insert(a, h, i, a[i]);
}
}
}