题解 | #字符串加密#哈希

import java.util.*;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);

        String secret = in.nextLine();
        Map<Character, Character> dictionary = getDictionary(secret);

        String text = in.nextLine();
        text = encrypt(text, dictionary);
        System.out.println(text);
    }

    private static Map<Character, Character> getDictionary(String secret) {
        // 去重
        LinkedHashSet<Character> set = new LinkedHashSet<>();
        for (int i = 0; i < secret.length(); i++) {
            set.add(secret.charAt(i));
        }
        // 加密替换
        HashMap<Character, Character> map = new HashMap<>();
        Iterator<Character> iterator = set.iterator();
        char value = 'a';
        for (int i = 0; i < 26; i++) {
            char key = (char) ('a' + i);
            if (iterator.hasNext()) {
                map.put(key, iterator.next());
            } else {
                while (set.contains(value) && value <= 'z') {
                    ++value;
                }
                map.put(key, value);
                value++;
            }
        }

        return map;
    }

    private static String encrypt(String text,
                                  Map<Character, Character> dictionary) {
        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < text.length(); i++) {
            char c = text.charAt(i);
            if (dictionary.containsKey(c)) {
                builder.append(dictionary.get(c));
            } else {
                builder.append(c);
            }
        }
        return builder.toString();
    }
}