Question

C++

There is a class called Person which has name and age as private variables.

Another class called Student, which is derived from person with gpa and id as variables.

name is a string, age and id are integers and gpa is a double... All of them are private variables.

age, gpa and id should be generated randomly when the object is created with the following ranges:

age 20 to 32

gpa 0.0 to 4.0 // this one is tricky to get as random doesnt generate decimal numbers.

id 1000 to 9999

In the start of the program, you will ask for how many students there are. dynamically create an array of students of that size. (we are not creating an object of type person for this test).

In a loop, you will ask for the names of each of these people (all the other data was already created randomly through the constructors).

Once you are done, you are to display everyone in the array neatly.

Sort the students by gpa (from highest to lowest, make sure you sort the students not just swapping of gpa) (do not use the bubbleish sort used in the review for test. look up the exact way to code Bubblesort in the book.

and display the sorted array neatly. (show the Students, not just the GPA's).

Answer 1

Answer:

#include <iostream>
#include <iomanip>
#include <string>
#include <cstdlib>
#include <ctime>
using namespace std;
class Person{
private:
string name;
int age;
public:
Person(){
name = "";
age = 20 + rand() % 13;
}
Person(string name){
age = 20 + rand() % 13;
}
string getName(){return name;}
int getAge() { return age;}
void setName(string n){ name = n;}
};

class Student: public Person{
private:
int id;
double gpa;
public:
Student(){
id = 1000 + rand() % 9000;
int x = rand() % 101; //generate a number from 0 - 100
gpa = x/100.0 * 4.0;
}
Student(string name):Person(name){
id = 1000 + rand() % 9000;
int x = rand() % 101; //generate a number from 0 - 100
gpa = x/100.0 * 4.0;
}
int getId() {return id;}
double getGPA() { return gpa;}
};

void displayStudents(Student *s, int n);
void sortStudents(Student *s, int n);

int main(){
int n;
Student *s;
string name;
cout << "How many students? ";
cin >> n;
s = new Student[n];
for(int i = 0; i < n; i++){
cout << "Enter name for student " << (i+1) << ": ";
cin >> name;
s[i].setName(name);
}
cout << "Before sorting the student list is " << endl;
displayStudents(s, n);
sortStudents(s, n);
cout << "After sorting the student list is " << endl;
displayStudents(s, n);
delete []s;
}
void displayStudents(Student *s, int n){
cout << setw(15) << "Name" << setw(10) << "ID" << setw(10) << "Age" << setw(10) << "GPA" << endl;
cout << fixed << setprecision(1);
for(int i = 0; i < n; i++)
cout << setw(15) << s[i].getName() << setw(10) << s[i].getId() << setw(10) << s[i].getAge()
<< setw(10) << s[i].getGPA() << endl;
cout << endl;
}
void sortStudents(Student *s, int n){
int i, j;
Student key;
//insertion sort descending order of gpa
for(i = 1; i < n; i++ ){
j = i - 1;
key = s[i];
while(j >= 0 && key.getGPA() < s[j].getGPA()){
s[j+1] = s[j];
j--;
}
s[j+1] = key;
}
}