题解 | 字符串加密

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 sc = new Scanner(System.in);
        String str = sc.nextLine();
        String str1 = sc.nextLine();
        Set<Character> set = new LinkedHashSet<>();// set不重复 LinkedHashSet有序添加        
        for (int i = 0; i < str.length(); i++) {
            char ch = str.charAt(i);
            set.add(ch);
        }
        for (int i = 97; i <= 122; i++) {
            char c = (char) i;
            set.add(c);                         // set不重复 LinkedHashSet有序添加                     
        }
        StringBuilder res = new StringBuilder();
        for (int i = 0; i < str1.length(); i++) {
            int temp = str1.charAt(i)-97;       // 求出在[a-z]的下标
            res.append(set.toArray()[temp]);    
        }
        System.out.println(res);
    }
}