题解 | #字符串加密#

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Scanner;
import java.util.stream.Collectors;

// 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 nextLine = in.nextLine();
            if (Objects.isNull(nextLine) || nextLine.equals("")) {
                break;
            }
            String str = in.nextLine();

            List<String> stringList = new ArrayList<>();
            for (int i = 'A'; i <= 'Z'; i++) {
                stringList.add((char) i + "");
            }
            // System.out.println(stringList);
            List<String> collect = nextLine.chars()
                .mapToObj(item -> ("" + (char) item).toUpperCase())
                .distinct()
                .collect(Collectors.toList());
            List<String> subList = stringList.stream()
                .filter(item -> !collect.contains(item))
                .collect(Collectors.toList());
            collect.addAll(subList);
            Map<String, String> map = new HashMap<>();
            for (int i = 0; i < stringList.size(); i++) {
                map.put(stringList.get(i), collect.get(i));
            }
            // System.out.println(map);
            System.out.println(str.chars()
                .mapToObj(item -> ("" + (char) item).toUpperCase())
                .map(item -> {
                    if (Objects.nonNull(map.get(item))) {
                        return map.get(item)
                            .toLowerCase();
                    }
                    return item.toLowerCase();
                })
                .collect(Collectors.joining()));
        }
    }
}