题解 | #简单密码#

public class Main{
    public static void main(String[] args){
        Scanner sc= new Scanner(System.in);
        StringBuffer s=new StringBuffer(sc.nextLine());
        //记录初始长度
        int l=s.length();
        //对每个元素分情况判断
        for(int i=0;i<l;i++){
            char temp=s.charAt(i);
            if(temp>='0'&&temp<='9')s=s.append(Character.toString(temp));
            else if(temp>='A'&&temp<'Z'){
                s=s.append(Character.toString((char)(temp+'a'-'A'+1)));
            }
            else if(temp=='Z')s=s.append("a");
            else if(temp>='a'&&temp<='z'){
                int n=temp-'a';
                if(n>='a'-'a'&&n<='c'-'a')s.append(Integer.toString(2));
                if(n>='d'-'a'&&n<='f'-'a')s.append(Integer.toString(3));
                if(n>='g'-'a'&&n<='i'-'a')s.append(Integer.toString(4));
                if(n>='j'-'a'&&n<='l'-'a')s.append(Integer.toString(5));
                if(n>='m'-'a'&&n<='o'-'a')s.append(Integer.toString(6));
                if(n>='p'-'a'&&n<='s'-'a')s.append(Integer.toString(7));
                if(n>='t'-'a'&&n<='v'-'a')s.append(Integer.toString(8));
                if(n>='w'-'a'&&n<='z'-'a')s.append(Integer.toString(9));
            }
        }
        //删除原始字符串
        s.delete(0,l);
        System.out.print(s.toString());
    }
}