1036 Boys vs Girls (25 分)

1. 题目

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−gradeM. 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

2. 题意

输入n名学生（信息包含：姓名、性别、学号、成绩），找出学生中，女生成绩最高和男生成绩最低的两位，并输出两人的成绩差。如果n名学生中没有男生或女生，输出Absent，且成绩差输出NA。

3. 思路——简单模拟

1. 学生信息用结构体存储

2. 初始时女生最高成绩为-1，这样只要有女生成绩比其高，就会更新；

   同理初始时男生最低成绩为101，这样只要只要男生成绩比其低，就会更新；

   如果最后最高成绩依旧为-1，说明n名学生中没有女生；

   如果最后最低成绩依旧为101，说明n名学生中没有男生。

4. 代码

#include <iostream>
#include <string>

using namespace std;

// 构建一个学生信息结构体，包含姓名、性别、ID号、成绩相关信息 
typedef struct stu
{
	string name;
	char gender;
	string ID;
	int grade;
} Stu;

int main()
{
	int n;
	cin >> n;

	Stu student;
	Stu femaleRes, maleRes;
	// 因为女生要找成绩最大值，将其grade置为-1，凡是成绩大于-1即更新女生结果 
	femaleRes.grade = -1;
	// 因为男生要找成绩最小值，将其grade置为101，凡是成绩小于101即更新男生结果 
	maleRes.grade = 101;
	while (n--)
	{
		cin >> student.name >> student.gender >> student.ID >> student.grade;
		if (student.gender == 'F')
		{
			if (student.grade > femaleRes.grade)
				femaleRes = student;
		} else
		{
			if (student.grade < maleRes.grade)
				maleRes = student;
		}
	}
	// 这里通过看男女生成绩是否还是-1或101， 来判断学生列表中国是否 
	if (femaleRes.grade == -1) cout << "Absent" << endl;
	else cout << femaleRes.name	<< " " << femaleRes.ID << endl;
	if (maleRes.grade == 101) cout << "Absent" << endl;
	else cout << maleRes.name << " " << maleRes.ID << endl;
	if (femaleRes.grade	!= -1 && maleRes.grade != 101)
		cout << femaleRes.grade	- maleRes.grade << endl;
	else cout << "NA" << endl; 
}