题解 | #字符串加密#

import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;

// 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);
        while (in.hasNextLine()) {
            String key = in.nextLine();
            if (key.isEmpty()) {
                break;
            }
            String str = in.nextLine();
            char[] encrypt = new char[26];
            Set<Character> set = new HashSet<>();
            int k = 0;
            for (int i = 0; i < key.length(); i++) {
                if (set.add(key.charAt(i))) {
                    encrypt[k] = key.charAt(i);
                    k++;
                }
            }
            // 26长度数组下标加上'a'即 (char)('a'+i) 就是字母表
            char alphabet;
            for (int i = 0; i < 26; i++) {
                alphabet = (char)('a' + i);
                if (!set.contains(alphabet)) {
                    encrypt[k] = alphabet;
                    k++;
                }
            }
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < str.length(); i++) {
                sb.append(encrypt[str.charAt(i) - 'a']);
            }

            System.out.println(sb);
        }
        in.close();
    }
}