题解 | #简单密码#

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str = br.readLine();
        StringBuffer sb = new StringBuffer();
        // 小写字母映射数组
        int[] map = {2,2,2,3,3,3,4,4,4,5,5,5,6,6,6,7,7,7,7,8,8,8,9,9,9,9};
        for(char c : str.toCharArray()){
            if(Character.isDigit(c)){
                sb.append(c);
            } else if(Character.isLetter(c)){
                if (c >= 97 && c <= 122){
                    // 映射小写字母
                    int s = map[c - 'a'];
                    sb.append(s);
                } else if(c >= 65 && c <= 89){
                    // 映射大写字母，除了Z
                    c = Character.toLowerCase(c);
                    c++;
                    sb.append(c);
                } else {
                    // 映射大写字母Z
                    sb.append('a');
                }
            }
        }
        System.out.println(sb.toString());
    }
}