算法题3

摘自传智播客公开课

package test;
import java.util.Scanner;
public class Arithmetic3 {
      
    //题设：某门户网站，具有如下业务功能
            //          客户输入个人信息时，当输入年龄，会根据输入的年龄值
            //          显示其所属年龄段
            
            //问题：上述业务日均访问量超百万次，设计完成上述功能的程序
            //百万次访问次数多，要求速度最快，一定是速度优先，时间尽量少
      
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int num = sc.nextInt();
          
        
        //方案一
        System.out.print("方案一：");
        if(0<num&&num<9) {
            System.out.println("儿童");
        }else if(num<19) {
            System.out.println("少年");
        }else if(num<29) {
            System.out.println("青年");
        }else if(num<39) {
            System.out.println("青壮年");
        }else if(num<49) {
            System.out.println("壮年");
        }else if(num<59) {
            System.out.println("中年");
        }else if(num<69) {
            System.out.println("中老年");
        }else if(num<79) {
            System.out.println("老年");
        }else if(num<89) {
            System.out.println("老老年");
        }else if(num<99) {
            System.out.println("老老老年    ");
        }else {
            System.out.println("error!!!");
        }
        System.out.println("-------------");
          
        //方案二
        System.out.print("方案二：");
        switch(num/10) {
        case 0:
            System.out.println("儿童");
            break;
        case 1:
            System.out.println("少年");
            break;
        case 2:
            System.out.println("青年");
            break;
        case 3:
            System.out.println("青壮年");
            break;
        case 4:
            System.out.println("壮年");
            break;
        case 5:
            System.out.println("中年");
            break;
        case 6:
            System.out.println("中老年");
            break;
        case 7:
            System.out.println("老年");
            break;
        case 8:
            System.out.println("老老年");
            break;
        case 9:
            System.out.println("老老老年");
            break;
        default:
            System.out.println("error!!!");
        }
        System.out.println("-------------");
          
        //方案三
        System.out.print("方案三：");
        String[] strArry = {"儿童","少年","青年","青壮年","壮年","中年","中老年","老年","老老年","老老老年"};
        System.out.println(strArry[num/10]);
    }
}