幼儿园分班

说明：不喜欢的人不能分在一起，查询是否有解决方案

思路：无法分班的情况是，当一个班级同时包含两个不喜欢的人时就无法分班

代码：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;

public class Client {


    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int n = Integer.parseInt(br.readLine());

        String[] strs = new String[n];
        for (int j = 0; j < n; j++) {
            strs[j] = br.readLine();
        }
        boolean suc = true;
        HashSet<String> class1 = new HashSet<>();
        HashSet<String> class2 = new HashSet<>();
        for (String str : strs) {
            int ticket = calc(str,class1,class2);
            if(ticket == 0){
                suc = false;
                break;
            }
        }
        if(suc){
            System.out.println(1);
        }else {
            System.out.println(0);
        }

    }
    private static int calc(String str, HashSet<String> class1, HashSet<String> class2) {
        String[] split = str.split(" ");
        String one = split[0];
        String two = split[1];
        if(class1.contains(one) && class1.contains(two)){
            return 0;
        }
        if(class2.contains(one) && class2.contains(two)){
            return 0;
        }
        class1.add(one);
        class2.add(two);
        return 1;
    }

}