第四天算法设计

希尔排序
需求：
排序前：{9,1,2,5,7,4,8,6,3,5}
排序后：{1,2,3,4,5,5,6,7,8,9}
算法设计
Shell类：
package suanfa;

public class Shell {
public static void sort(Comparable[] a){

    // 先确定增长量
    int h = 1;
    while(h < a.length / 2) {
        h = 2 * h + 1;
    }

    // 按照 h 值进行排序
    while(h >= 1){

        for(int i = h; i < a.length; i++) {
            for(int j = i; j >= h; j -= h) {
                if(greater(a[j - h], a[j])) {
                    exch(a, j - h, j);
                } else {
                    break;
                }
            }
        }

        h = h / 2;
    }
}

private static boolean greater(Comparable v, Comparable w) {
    return v.compareTo(w) > 0;
}

private static void exch(Comparable[] a, int i, int j) {
    Comparable temp = a[i];
    a[i] = a[j];
    a[j] = temp;
}

}

ShellTest类：
package suanfa;

import java.util.Arrays;

public class ShellTest {
public static void main(String[] args) {
Integer[] a={9,1,2,5,7,4,8,6,3,5};
Shell.sort(a);
System.out.println(Arrays.toString(a));
}
}
录制: untitled2 – Shell.java
录制文件：https://meeting.tencent.com/crm/ldR1Qz8Pfb