题解 | #字符串加密#

java LinkedHashSet

import java.util.*;
public class Main {
        public static void main(String[] args) {
            Scanner sc = new Scanner(System.in);
            while(sc.hasNextLine()) {
                String key = sc.nextLine();
                String msg = sc.nextLine();
                int length = key.length();
                Set<Character> set = new LinkedHashSet<Character>();
                for (int i = 0; i < key.length(); i++) {
                    set.add(key.charAt(i));
                }
                char start = 'a';
                for (int i = 0; i < 26; i++) {
                    set.add(start);
                    start += 1;
                }
                ArrayList<Character> list = new ArrayList<>(set);
                StringBuilder sb = new StringBuilder();
                char[] arr = msg.toCharArray();
                for (int i=0; i< arr.length; i++) {
                    if (arr[i] >= 'A' && arr[i] <= 'Z') {
                        int tmp = arr[i] - 'A';
                        sb.append(String.valueOf(list.get(tmp)).toUpperCase());
                    } else {
                        int tmp = arr[i] - 'a';
                        sb.append(String.valueOf(list.get(tmp)).toLowerCase());
                    }
                }
                System.out.println(sb.toString());
                
            }
         }
}