Question

I am self-learning C++ from a text book and I have a problem to solve, outlined below.

I have the following class structure:

 #include <iostream>
 #include <cstdio>
 #include <ctime> 

 using namespace std;


   class classroom{

     char name[25];
     int student_id;
     float grades[10];
     float average;
     int num_tests;
     float letter_grade;

   public:       
     void enter_name_id(void);
     void enter_grade(void);
     void average_grades(void);
     void letter_grades(void);
     void output_name_id_grade(void);
     classroom();

   };

And I have the following Constructor for the above class:

 classroom::classroom(){

      int i;

      srand((unsigned)time(0));
      int random_integer=0; 
      random_integer = (rand()%5) + (rand()%5); 

      num_tests=0;
      average=0.0;

      for(i=0;i<10;i++){

        grades[i]=0.0;

      }

      for(i=0;i<27;i++){

         name[i]='-';       
      }
      cout<<"\n*****************Finished*****************";
 }

There will be 3 students of this class structure declared in the main:

int main()
{       
  classroom students[3]; 
//and so...

}

I need to generate a unique student ID for each student in the constructor within a range of values, say, 0 to 10.

I have copied the following code snippet into the constructor. It generates my random number for me within the desired range:

srand((unsigned)time(0));
  int random_integer=0; 
  random_integer = (rand()%5) + (rand()%5);

The problem is that I need to get rid of any duplicates within the range of random numbers that are generated.

Answer 1

Why does the number need to be random? Can’t you just use a static int that gets incremented every time you need to generate a new student number?