Question

Why am I getting the same results with my rand() every time I run my C++ program?

I am trying to do this problem:

each receive $200 per week plus 9 percent of their gross sales for that week. For example, a salesperson who grosses $5000 in sales in a week receives $200 plus 9 percent of $ 5000, or a total of $650. Write a program(using an array of counters) that determines how many of the salespeople earned salaries in each of the following ranges (assume that each salesperson's salary is truncated to an integer amount.

In my code I am calculating this with a rand() * 0.09 in order to get a random gross number to get 9 percent of for the problem. However, everytime I run it I get the same numbers. Also, what is an array counter exaclty? And am I using one correctly??

#include<iostream>
#include<array>

using namespace std;

int main() {
  
   double grossales, salary,counterA=0,counterB=0,counterC=0,counterD=0;
   double counterE=0, counterF=0, counterG=0, counterH=0, counterI=0;

   array<double, 5> money{};

   for (int i = 1; i < 5; i++) {

       grossales = rand() * 0.09;

       salary = 200 + grossales;

       money[i] = salary;
   }

   for (int j = 1; j < 5; j++)
       cout << money[j] << endl;

   for (int k = 1; k < 5; k++) {

       if (money[k] >= 200 && money[k] <= 299)
           counterA++;
       else if (money[k] >= 300 && money[k] <= 399)
           counterB++;
       else if (money[k] >= 400 && money[k] <= 499)
           counterC++;
       else if (money[k] >= 500 && money[k] <= 599)
           counterD++;
       else if (money[k] >= 600 && money[k] <= 699)
           counterE++;
       else if (money[k] >= 700 && money[k] <= 799)
           counterF++;
       else if (money[k] >= 800 && money[k] <= 899)
           counterG++;
       else if (money[k] >= 900 && money[k] <= 999)
           counterH++;
       else if (money[k] >= 1000)
           counterI++;
   }

   cout << "The results are:" << endl;

   cout << "A: " << counterA << endl;
   cout << "B: " << counterB << endl;
   cout << "C: " << counterC << endl;
   cout << "D: " << counterD << endl;
   cout << "E: " << counterE << endl;
   cout << "F: " << counterF << endl;
   cout << "G: " << counterG << endl;
   cout << "H: " << counterH << endl;
   cout << "I: " << counterI << endl;
}

Answer 1

You have missed a line in main program to include.

int main()

{

srand(time(NULL));

//Rest of code

}

If you not include srand function than each time you will get the same number from rand() function.