站在巨人肩膀上的答案，善用map和set

参考答案：mans0n

import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        System.out.print(decode(sc.nextLine()));
        
    }
    
    public static String decode(String str){
        Map<String, String> map = new HashMap<>();
        map.put("1","1");
        map.put("abc","2");
        map.put("def","3");
        map.put("ghi","4");
        map.put("jkl","5");
        map.put("mno","6");
        map.put("pqrs","7");
        map.put("tuv","8");
        map.put("wxyz","9");
        map.put("0","0");
        char[] charArr = str.toCharArray();
        StringBuilder sb = new StringBuilder();
        for(char c : charArr){
            if(c >= '0' && c <= '9')
                sb.append(c);
            else if(c >= 'A' && c <= 'Y'){
                sb.append((char)(c+33));
            }
            else if(c == 'Z')
                sb.append('a');
            else{
                Set<String> keys = map.keySet();
                for(String k : keys){
                    if(k.contains(String.valueOf(c)))
                        sb.append(map.get(k));
                }
            }
        }
        return sb.toString();
    }
}