JAVA练习：罗马数字

题目：

1.实现思路:

2.实现截图：

3.代码：

import java.util.Scanner;
public class zhlmsz {
    public static void main(String[] args) {
        String oldabc;
        while(true){
        System.out.println("请输入一个字符串：");
        Scanner sc = new Scanner(System.in);
        String abc = sc.next();
        if (pd(abc)==true) {
        oldabc=abc;
            break;
        }else if(pd(abc)==false){
            System.out.println("当前字符串不符合规则，请重新输入：");
            continue;
        }
        }


        String newabc="";
        for (int i = 0; i < oldabc.length(); i++) {
            newabc=newabc+lmsz(szzh(oldabc.charAt(i)));
            newabc+=" ";
        }
        System.out.println(newabc);
        }

        public static boolean pd(String a){
        if(a.length()>9){return false;}
            for (int i = 0; i < a.length(); i++) {
                if(a.charAt(i)<'0'||a.charAt(i)>'9'){
                    return false;
                }
            }
            return true;
        }
        public static String lmsz(int a){
            String[] aaa = {" ", "Ⅰ", "Ⅱ", "Ⅲ", "Ⅳ", "Ⅴ", "Ⅵ", "Ⅶ", "Ⅷ", "Ⅸ"};
            return aaa[a];
        }
        public static int szzh(char a){
            int c=0;
            c=a-48;
            return c;
        }
    }

import java.util.Scanner;
public class zhlmsz {
    public static void main(String[] args) {
        String oldabc;
        while(true){
        System.out.println("请输入一个字符串：");
        Scanner sc = new Scanner(System.in);
        String abc = sc.next();
        if (pd(abc)==true) {
        oldabc=abc;
            break;
        }else if(pd(abc)==false){
            System.out.println("当前字符串不符合规则，请重新输入：");
            continue;
        }
        }


        String newabc="";
        for (int i = 0; i < oldabc.length(); i++) {
            newabc=newabc+lmsz(oldabc.charAt(i));
            newabc+=" ";
        }
        System.out.println(newabc);
        }

        public static boolean pd(String a){
        if(a.length()>9){return false;}
            for (int i = 0; i < a.length(); i++) {
                if(a.charAt(i)<'0'||a.charAt(i)>'9'){
                    return false;
                }
            }
            return true;
        }
        public static String lmsz(char a){
            switch(a){
                case '0':
                return " ";
                case '1':
                return "Ⅰ";
                case '2':
                return "Ⅱ";
                case '3':
                return "Ⅲ";
                case '4':
                return "Ⅳ";
                case '5':
                return "Ⅴ";
                case '6':
                return "Ⅵ";
                case '7':
                return "Ⅶ";
                case '8':
                return "Ⅷ";
                case '9':
                return "Ⅸ";
                default:
                return "";
            }
        }
    }