题解 | #字符串加密#

import java.util.*;

public class HJ36 {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String key = in.nextLine();
            String toEncrypt = in.nextLine();
            String encryptedStr = encrypt(key, toEncrypt);
            System.out.println(encryptedStr);
        }
    }

    public static String encrypt(String key, String toEncrypt) {
        // 初始字典表
        Character[] keyTable = initKeyTable(key);
        StringBuilder result = new StringBuilder(toEncrypt.length());
        for (Character ch : toEncrypt.toCharArray()) {
            result.append(keyTable[Character.toLowerCase(ch) - 'a']);
        }
        return result.toString();
    }

    /**
     * 生成密钥表
     *
     * @param key 密钥
     * @return 密钥表
     */
    public static Character[] initKeyTable(String key) {
        Character[] keyTable = new Character[26];
        String keyLowerCase = key.toLowerCase(Locale.ROOT);
        Set<Character> addedKeys = new LinkedHashSet<>(26);
        // 先添加本字符串key
        for (Character ch : keyLowerCase.toCharArray()) {
            addedKeys.add(ch);
        }
        // 添加其余字符
        for (char i = 'a'; i <= 'z'; i++) {
            addedKeys.add(i);
        }
        addedKeys.toArray(keyTable);
        return keyTable;
    }
}