Question

Problem: The spread of disease through a community has been determined to follow the formula Current_Infected = Initial_Infected * e^0.8t where t is the time in days

. Prompt the user to enter the initial (day 0) number of infected people and number of days to considered. The number of infected should be a floating point number and the number of days should be a whole number. Use while loops to confirm robustly that the initial number of infected and the number of days are positive number, you should assume the user enters values of appropriate data types. Create a table from day 0 to entered days and current infected using a for loop. Use formatting to line up the columns and to output the number of infected to 5 significant figures. Make sure that you include column headings. Do not create a variable or constant for e, instead use the appropriate built-in function to calculate the current infected.

using: C++ visual studio

Answer 1

The program plan:

• Ask the user for the correct input of infections and number of days using a while loop
• Assign memories for days and infections
• Calculate infection on each day using the given equation
• Display the table at last.

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The c++ code:

#include <iostream>
#include <cmath>
using namespace std;

int main()
{
   double initialCount;
   int i, d;
   while (true) //loop till correct input is given
   {
       cout << "Enter the number of infected people : ";
       cin >> initialCount; //take input of infected people
       if (initialCount > 0)
           break;
       else
           cout << "\t||Error : Number of people are not positive.\n";
   }

   while (true) //loop till correct input is given
   {
       cout << "Enter the number of days : ";
       cin >> d; //take input of number of days
       if (d > 0)
           break;
       else
           cout << "\t||Error : Number of days are not positive.\n";
   }

   int* days = new int[d + 1]; //assign memory for day 0 to d
   double* counts = new double[d + 1]; //assign memory for infection count

   for (i = 0; i <= d; i++)
   {
       days[i] = i;
       counts[i] = initialCount * exp(0.8 * i); //calculate the infections for day i
   }

   //display the table below
   cout << "\nDays\tInfection Count\n";
   cout.precision(5); //sets maximum precision to 5 significant digits
   for (i = 0; i <= d; i++)
   {
       cout << days[i] << "\t" << counts[i] << "\n";
   }

   return 0;
}

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Code Screenshot:

#include <iostream> [#include <cmath> using namespace std; int main() { 1 2 3 4 5 6 7 8 9 10 11 12 13 14 double initialCount; int i, d; while (true) //loop till correct input is given بها cout << "Enter the number of infected people : "; cin >> initialCount; //take input of infected people if (initialCount > 0) break; else cout << "\t||Error : Number of people are not positive."; 15 16 17 18

while (true) //loop till correct input is given cout << "Enter the number of days : "; cin >> d; //take input of number of days if (d > 0) break; else cout << "\t||Error : Number of days are not positive."; 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 int* days = new int[d + 1]; //assign memory for day to d double* counts = new double[d + 1]; //assign memory for infection count for (i = 0; i <= d; i++) { days[i] = i; counts[i] = initialCount * exp(0.8 * i); //calculate the infections for day i mething

//display the table below cout << "\nDays\tInfection Count\n"; cout.precision (5); for (i = 0; i <= d; i++) { 38 39 40 41 42 43 44 45 46 47 cout << days[i] << "\t" «counts[i] << "\n"; melang return;

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Output:

Microsoft Visual Studio Debug Console Enter the number of infected people : 10 Enter the number of days : 10 Days 0 1 2 3 4 5 6 7 8 9 10 Infection Count 10 22.255 49.53 110.23 245.33 545.98 1215.1 2704.3 6018.5 13394 29810 C:\Users\ADARSH ANURAG\source repos\ConsoleApplicat: To automatically close the console when debugging st le when debugging stops. Press any key to close this window

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Stay safe. Stay immune.