2023/2/1

很简单的题，为了减少内存用了数组没用map。

public String decodeMessage(String key, String message) {
        char[] set = new char[26];
        StringBuilder sb = new StringBuilder();
        int count = 0;
        for(int i = 0;i<key.length();i++) {
            if(key.charAt(i) == ' '){
                continue;
            }
            if(set[key.charAt(i)- 'a'] == (char) 0 ) {
                set[key.charAt(i) - 'a'] = (char) ('a' + count);
                count++;
            }
        }
        for(int i = 0; i < message.length();i++){
            if(message.charAt(i) == ' '){
                sb.append(" ");
            }else {
                sb.append(set[message.charAt(i) - 'a']);
            }
        }
        return sb.toString();
    }