Question

5.11: Population Write a program that will predict the size of a population of organisms. The program should ask the user for the starting number of organisms, their average daily population increase (as a percentage, expressed as a fraction in decimal form: for example 0.052 would mean a 5.2% increase each day), and the number of days they will multiply. A loop should display the size of the population for each day.

Answer 1

Answer:

// using c++ language

#include "stdafx.h";

#include <iostream>

#include<cmath>

using namespace std;

//start

int main()

{

  //Declaration of variables in the program

  double start_organisms;

  double daily_increase;

  int days;

  double updated_organisms;

  //The user enters the number of organisms as desired

  cout << "Enter the starting number of organisms: ";

  cin >> start_organisms;

  //Validating input data

  while (start_organisms < 2)

  {

      cout << "The starting number of organisms must be at least 2.\n";

      cout << "Enter the starting number of organisms: ";

      cin >> start_organisms;

  }

  //The user enters daily input, here's where we apply the 5.2% given in question

  cout << "Enter the daily population increase: ";

  cin>> daily_increase;

  //Validating the increase

  while (daily_increase < 0)

  {

      cout << "The average daily population increase must be a positive value.\n ";

      cout << "Enter the daily population increase: ";

      cin >> daily_increase;

  }

  //The user enters number of days

  cout << "Enter the number of days: ";

  cin >> days;

  //Validating the number of days

  while (days<1)

  {

      cout << "The number of days must be at least 1.\n";

      cout << "Enter the number of days: ";

      cin >> days;

  }

 

  //Final calculation and display of results based on formulas

  for (int i = 0; i < days; i++)

  {

      updated_organisms = start_organisms + (daily_increase*start_organisms);

      cout << "On day " << i + 1 << " the population size was " << round(updated_organisms)<<"."<<"\n";

     

      start_organisms = updated_organisms;

  }

  system("pause");

   return 0;

//end

}