(用JAVA语言)编写一个程序用选择法对数组a[]={20,10,50,40,30,70,60...答:public class Demo { public static void main(String args[]) { int arr[] = {20,10,50,40,30,70,60,80,90,100};System.out.println("数组由大到小排序前:");for(int num : arr) { System.out.print(num + "、");} //使用冒泡排序法,将数组由大到小进行排序 for(int i = ...