PAT (Advanced Level) Practice 1036 Boys vs Girls

【Problem Description】:
This time you are asked to tell the difference between the lowest grade of all the male students and the highest grade of all the female students.
【Input Specification】:
Each input file contains one test case. Each case contains a positive integer N, followed by N lines of student information. Each line contains a student’s name, gender, ID and grade, separated by a space, where name and ID are strings of no more than 10 characters with no space, gender is either F (female) or M (male), and grade is an integer between 0 and 100. It is guaranteed that all the grades are distinct.
【Output Specification】:
For each test case, output in 3 lines. The first line gives the name and ID of the female student with the highest grade, and the second line gives that of the male student with the lowest grade. The third line gives the difference gradeF​​−grade​M​​. If one such kind of student is missing, output Absent in the corresponding line, and output NA in the third line instead.
【Sample Input 1】:
3
Joe M Math990112 89
Mike M CS991301 100
Mary F EE990830 95
【Sample Output 1】:
Mary EE990830
Joe Math990112
6
【Sample Input 2】:
1
Jean M AA980920 60
【Sample Output 2】:
Absent
Jean AA980920
NA

【C++代码】

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
using namespace std;
struct student {
	string name;
	char gender;
	string ID;
	int grade;
};
bool compare1(student a,student b) {	//女生按成绩从高到低排序
	return a.grade>b.grade;
}
bool compare2(student a,student b) {	//男生按成绩从低到高排序
	return a.grade<b.grade;
}
int main() {
	bool flag=true;
	int n,fcnt=0,mcnt=0;
	student stu;
	vector<student> vf;
	vector<student> vm;
	cin>>n;
	while(n--) {
		cin>>stu.name>>stu.gender>>stu.ID>>stu.grade;
		if(stu.gender=='F') {
			vf.push_back(stu);
			fcnt++;
		} else {
			vm.push_back(stu);
			mcnt++;
		}
	}
	if(fcnt==0) {	//女生缺席
		cout<<"Absent"<<endl;
		flag=false;
	} else {
		sort(vf.begin(),vf.end(),compare1);
		cout<<vf[0].name<<" "<<vf[0].ID<<endl;
	}
	if(mcnt==0) {	//男生缺席
		cout<<"Absent"<<endl;
		flag=false;
	} else {
		sort(vm.begin(),vm.end(),compare2);
		cout<<vm[0].name<<" "<<vm[0].ID<<endl;
	}
	if(flag) cout<<vf[0].grade-vm[0].grade<<endl;
	else cout<<"NA"<<endl;
	return 0;
}

【Java代码】

import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;
import java.util.Vector;
class Student {
	String name;
	String gender;
	String ID;
	int grade;
}
class StudentComparator1 implements Comparator<Student> {
	@Override
	public int compare(Student o1,Student o2) {
		return o2.grade - o1.grade;
	}
}
class StudentComparator2 implements Comparator<Student> {
	@Override
	public int compare(Student o1,Student o2) {
		return o1.grade - o2.grade;
	}
}
public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		List<Student> vf = new Vector<Student>();
		List<Student> vm = new Vector<Student>();
		boolean flag = true;
		int n = scan.nextInt();
		int fcnt = 0, mcnt = 0;
		for(int i = 0; i < n; i++) {
			Student temp = new Student();
			temp.name = scan.next();
			temp.gender = scan.next();
			temp.ID = scan.next();
			temp.grade = scan.nextInt();
			if("F".equals(temp.gender)) {
				vf.add(temp);
				fcnt++;
			} else {
				vm.add(temp);
				mcnt++;
			}
		}
		scan.close();
		if(fcnt==0) {	//女生缺席
			System.out.println("Absent");
			flag=false;
		} else {
			Collections.sort(vf,new StudentComparator1());
			System.out.println(vf.get(0).name + " " + vf.get(0).ID);
		}
		if(mcnt==0) {	//男生缺席
			System.out.println("Absent");
			flag=false;
		} else {
			Collections.sort(vm,new StudentComparator2());
			System.out.println(vm.get(0).name + " " + vm.get(0).ID);
		}
		if(flag) System.out.println(vf.get(0).grade-vm.get(0).grade);
		else System.out.println("NA");
	}
}