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  1. //Castulo Jason Quintero            CSC5          Chapter 6, Pg. 373, #15
  2. //
  3. /**************************************************************************
  4.  *
  5.  * Calculate Population Size
  6.  * ________________________________________________________________________
  7.  * This program recieves as user input the current population
  8.  * size, annual birth rate, annual death rate, and years
  9.  * requested to calculate the new population size each year.
  10.  *
  11.  * Computation is based on formula:
  12.  *  newPopulationsize = previousPopulationsize +
  13.  *  					(birthRate * previousPopulationsize) -
  14.  *  					(deathRate * previousPopulationsize)
  15.  * ________________________________________________________________________
  16.  * INPUT
  17.  *  previousPopulationsize    : Previous population size
  18.  *	birthRate                 : Annual birth rate percentage
  19.  *	deathRate                 : Annual death rate percentage
  20.  *	year                      : Years requesting to be displayed
  21.  *
  22.  * OUTPUT
  23.  *  year                      : Year being displayed with loop
  24.  *  newPopulationsize         : New size of population each year
  25.  *************************************************************************/
  26.  
  27. #include <iostream>
  28. #include <iomanip>
  29. using namespace std;
  30.  
  31. // Prototype
  32. float popSize(float, float, float);
  33.  
  34. // Main function
  35. int main()
  36. {
  37. 	float newPopulationsize;            // New population size
  38. 	float previousPopulationsize = 0;   // Previous population size
  39. 	float birthRate;                    // Annual birth rate percentage
  40. 	float deathRate;                    // Annual death rate percentage
  41. 	float year;                         // Years requesting to be displayed
  42.  
  43.     // Input for starting population
  44.     cout << "Please enter the starting size of the population: \n";
  45.     cin >> previousPopulationsize;
  46.  
  47.     // Input validation
  48.     while (previousPopulationsize < 2)
  49.     {
  50.     	cout << "Please enter a starting population that is atleast "
  51.     		 << "two people. \n";
  52.     	cin >> previousPopulationsize;
  53.     }
  54.  
  55.     // Input annual birth rate percentage
  56.     cout << "Please enter the annual birth rate percentage: \n";
  57.     cin >> birthRate;
  58.  
  59.     // Input validation
  60.     while (birthRate < 0)
  61.     {
  62.     	cout << "Please enter a non negative number for the birth rate \n";
  63.     	cin >> birthRate;
  64.     }
  65.  
  66.     // Input annual death rate percentage
  67.     cout << "Please enter the annual death rate percentage: \n";
  68.     cin >> deathRate;
  69.  
  70.     // Input validation
  71.     while (deathRate < 0)
  72.     {
  73.     	cout << "Please enter a non negative number for the birth rate \n";
  74.     	cin >> deathRate;
  75.     }
  76.  
  77.     // Input years to be displayed
  78.     cout << "Please enter the number of years to be displayed: \n";
  79.     cin >> year;
  80.  
  81.     // Input validation
  82.     while (year < 1)
  83.     {
  84.     	cout << "Please enter a value greater than 1 for the years to "
  85.     		 << "be displayed. \n";
  86.     	cin >> year;
  87.     }
  88.  
  89.     // For loop to give value for each year
  90. 	for (int i = 1; i <= year; i++)
  91. 	{
  92. 		newPopulationsize = popSize(previousPopulationsize, birthRate,
  93.     			                    deathRate);
  94.     	previousPopulationsize = newPopulationsize;
  95.  
  96.     	cout << setprecision(0) << fixed;
  97.     	cout << "The population for year " << i << " was "
  98.     	    << newPopulationsize << endl;
  99. 	}
  100. 	return 0;
  101. }
  102.  
  103. // Value return function and calculations
  104. float popSize (float P, float B, float D)
  105. {
  106. 	float N;
  107. 	B *= .01;                   // Converts to percentage
  108. 	D *= .01;                   // Converts to percentage
  109. 	N = P + (B * P) - (D * P);  // Formual to get new population
  110. 	return N;                   // Return value of N
  111. }
Success #stdin #stdout 0s 5304KB
comments (?)
stdin 
100 10 5 5
stdout 
Please enter the starting size of the population: 
Please enter the annual birth rate percentage: 
Please enter the annual death rate percentage: 
Please enter the number of years to be displayed: 
The population for year 1 was 105
The population for year 2 was 110
The population for year 3 was 116
The population for year 4 was 122
The population for year 5 was 128
https://ideone.com/J51pXa
language:
C++ (gcc 8.3)
created:
1 year ago
visibility:
secret

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