Calculate student grade (virtual function and polymorphism)

Catalog

Title Description

AC Code

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Title Description

Please design 3 Classes , They are students Student, Undergraduate class Undergraduate, Graduate students Postgraduate, among Student Class is the base class , It contains basic student information , Such as name 、 Category （ Undergraduate or graduate ）、 Courses learned （ It is assumed that 3 Course , Express in an array ） Grades and grades ;Undergraduate Classes and Postgraduate All are Student A derived class of the , The main difference between them is the calculation 3 There are different ways of grading the average grade of each course , The standard of postgraduates is higher than that of undergraduates , As shown in the following table ：

Undergraduate standards	Graduate standards
80~100 good	90~100 good
70~80 good	80~90 good
60~70 commonly	70~80 commonly
50~60 pass	60~70 pass
50 Fail below	60 Fail below

Student Student The base class framework is shown below ：

class Student{

protected:

string name; // The student's name

int type; // Student categories :1 Means undergraduate ,2 Indicates a graduate student

int courses[3]; //3 Results of courses

string courseGrade; // Grades

public:

Student(string n,string t,int a1,int a2,int a3);// Construction method

virtual void calculateGrade()=0;// Calculate grade

void print();// Output information

};

With Student Base class , build Undergraduate、Postgraduate Two classes .

Generate the above class and write the main function , Require a base class pointer in the main function , Generate base class dynamic array , To receive subclass objects .

Input

The first line indicates the number of tests . Start with the second line , One line per test case , The meaning of each line of data is as follows ： The student's name 、 Student categories （1 For undergraduates ,2 For graduate students ）、3 Results of courses .

Output

The student's name 、 Category 、 Grades

sample input 1 

sample output 1

AC Code

#include<iostream>
#include<string>
#include<algorithm>
#include<cmath>
#include<iomanip>
using namespace std;
class Student {
	protected:
		string name; // The student's name 
		int type; // Student categories :1 Means undergraduate ,2 Indicates a graduate student 
		int courses[3]; //3 Results of courses 
		string courseGrade; // Grades 
	public:
		Student(string n, int t, int a1, int a2, int a3): name(n), type(t) {
			courses[0] = a1;
			courses[1] = a2;
			courses[2] = a3;
		}// Construction method 
		virtual void calculateGrade() = 0; // Calculate grade 
		void print() {
			if (type == 1)
				cout << name << ", Undergraduate ," << courseGrade << endl;
			else
				cout << name << ", Graduate student ," << courseGrade << endl;
		}
};
class Undergraduate: public Student {
	public:
		Undergraduate(string n, int t, int a1, int a2, int a3): Student(n, t, a1, a2, a3) {}
		virtual void calculateGrade() {
			int average = (courses[0] + courses[1] + courses[2]) / 3;
			if (average >= 80)
				courseGrade = " good ";
			else if (average >= 70)
				courseGrade = " good ";
			else if (average >= 60)
				courseGrade = " commonly ";
			else if (average >= 50)
				courseGrade = " pass ";
			else
				courseGrade = " fail, ";
		}
};
class Postgraduate: public Student {
	public:
		Postgraduate(string n, int t, int a1, int a2, int a3): Student(n, t, a1, a2, a3) {}
		virtual void calculateGrade() {
			int average = (courses[0] + courses[1] + courses[2]) / 3;
			if (average >= 90)
				courseGrade = " good ";
			else if (average >= 80)
				courseGrade = " good ";
			else if (average >= 70)
				courseGrade = " commonly ";
			else if (average >= 60)
				courseGrade = " pass ";
			else
				courseGrade = " fail, ";
		}
};
int main() {
	int t, tpye, a, b, c, i;
	string name;
	cin >> t;
	i = t;
	Student** p = new Student*[t];
	while (t--) {
		cin >> name >> tpye >> a >> b >> c;
		if (tpye == 1)
			p[t] = new Undergraduate(name, tpye, a, b, c);
		else
			p[t] = new Postgraduate(name, tpye, a, b, c);
		p[t]->calculateGrade();
		p[t]->print();
	}
	if (p) {
		for (t = 0; t < i; t++)
			delete p[t];
		delete[] p;
	}
}