huawei-od-exercise-每日一练OD习题

package com.rep.str; import com.sun.xml.internal.ws.server.ServerRtException; import java.util.*; /* 有两门选修课，每门选修课都有一部分学生选修，每个学生都有选修课的成绩， 需要你找出同时选修了两门选修课的学生， 先按照班级进行划分，班级编号小的先输出 ，每个班级按照两门选修课成绩和的降序排序，成绩相同时按照学生的学号升序排序。 */ public class XuanXiu { public static class Student { String cNo; String sNo; int scoreCs1 = -1; int scoreCs2 = -1; public int getSum() { return scoreCs1 + scoreCs2; } } public static void main(String[] args) { Scanner scanner = new Scanner(System.in); String s1 = scanner.nextLine(); String s2 = scanner.nextLine(); getResult(s1, s2); } public static void getResult(String s1, String s2) { /* s1 01202021,75;01201033,95;01202008,80;01203006,90;01203088,100 s2 01202008,70;01203088,85;01202111,80;01202021,75;01201100,88 */ HashMap<String, Student> students = new HashMap<>(); divide(s1, 1, students); divide(s2, 2, students); // 查看是否有两个得分 Student[] suits = students.values().stream().filter( student -> student.scoreCs2 != -1 && student.scoreCs1 != -1 ).toArray(Student[]::new); if (suits.length == 0) { System.out.println("NULL"); return; } /* 结果 01202 班级号 01202008;01202021 学号 01203 01203088 */ HashMap<String, ArrayList<Student>> resp = new HashMap<>(); for (Student student : suits) { resp.putIfAbsent(student.cNo, new ArrayList<>()); resp.get(student.cNo).add(student); } // 排序 resp.keySet().stream().sorted().forEach( /* 先按照班级进行划分，班级编号小的先输出 ，每个班级按照两门选修课成绩和的降序排序，成绩相同时按照学生的学号升序排序。 */ cNo -> { System.out.println(cNo); ArrayList<Student> studentList = resp.get(cNo); studentList.sort((stu1, stu2) -> { int stu1Score = stu1.getSum(); int stu2Score = stu2.getSum(); return stu1Score - stu2Score; }); //输出学号 StringBuilder stringBuilder = new StringBuilder(); for (Student student : studentList) { stringBuilder.append(student.sNo + ";"); } stringBuilder.deleteCharAt(stringBuilder.length() - 1); System.out.println(stringBuilder); } ); } public static void divide(String str, int corseNo, Map<String, Student> map) { String[] stus = str.split(";"); for (String stu : stus) { int score = Integer.parseInt(stu.split(",")[1]); String cNo = stu.split(",")[0].substring(0, 5);// 班级号 String sNo = stu.split(",")[0];// 学号 map.putIfAbsent(sNo, new Student()); Student student = map.get(sNo); student.sNo = sNo; student.cNo = cNo; if (corseNo == 1) { student.scoreCs1 = score; } else { student.scoreCs2 = score; } } } }