希尔排序
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;
public class ShellSort {
public static void main(String[] args) {
int[] arr = new int[2000000];
for (int i = 0; i < 2000000; i++) {
arr[i] = (int) (Math.random() * 200000000);
}
System.out.println("排序前");
Date data1 = new Date();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS");
String date1Str = simpleDateFormat.format(data1);
System.out.println("排序前的时间是=" + date1Str);
shellSort2(arr);
Date data2 = new Date();
String date2Str = simpleDateFormat.format(data2);
System.out.println("排序前的时间是=" + date2Str);
}
public static void shellSort(int[] arr) {
int temp = 0;
int count = 0;
for (int gap = arr.length / 2; gap > 0; gap /= 2) {
for (int i = gap; i < arr.length; i++) {
for (int j = i - gap; j >= 0; j -= gap) {
if (arr[j] > arr[j + gap]) {
temp = arr[j];
arr[j] = arr[j + gap];
arr[j + gap] = temp;
}
}
}
}
}
public static void shellSort2(int[] arr) {
for (int gap = arr.length / 2; gap > 0; gap /= 2) {
for (int i = gap; i < arr.length; i++) {
int j = i;
int temp = arr[j];
if (arr[j] < arr[j - gap]) {
while (j - gap >= 0 && temp < arr[j - gap]) {
arr[j] = arr[j-gap];
j -= gap;
}
arr[j] = temp;
}
}
}
}
}