JAVA实现选择排序并测试

package day02_code.heima.algorithm.sort.selection;

import java.util.Arrays;

public abstract class Selection {
    public static void sort(Comparable[] a) {
        /*外层循环体现一共执行多少次*/
        for (int i = 0; i < a.length - 1; i++) {
            /*对于单次循环，设置最小值处索引minIndex,假设每次比较的第一位是最小值*/
            int minIndex = i;
            /*从i后面一位开始和i进行比较
             * j<a.length表示比较到最后一位为止*/
            for (int j = i + 1; j < a.length; j++) {
                /*比较最小处索引的值和j处索引值的大小*/
                if (greater(a[minIndex], a[j])) {
                    minIndex = j;
                }
            }
            exchange(a, i, minIndex);
        }
    }

    public static boolean greater(Comparable a, Comparable b) {
        return a.compareTo(b) > 0;
    }

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

    public static void main(String[] args) {
        Comparable[] a = {4, 5, 3, 2, 1};
        Selection.sort(a);
        System.out.println(Arrays.toString(a));
    }

}