// PROGRAM:		dcheung_agegroup.cpp
// PROGRAMMER:	David Cheung
// DATE:		11/28/06
// PURPOSE:		Prints an age group distribution table and bar graph
// INPUT:		Age
// OUTPUT:		Program function
//				Exit instruction
//				The age group distribution table
//				Age distribution bar graph
// DESCRIPTION:

/*	Algorithm:
 * 
 * 			Declare const int constOldest
 * 			Declare int varAge, loopHighestBar, loopXaxis, loopYaxis,
 * 						loopBarCountTop/Bottom and loopRangeSymbol variables
 * 			Declare int varAgeCount[13] array
 * 
 * 			** Variable input section **
 * 
 * 			Display Program function
 * 			Display Instructions for input and exit
 * 
 * 			Input varAge
 * 
 * 			while (varAge >= 0)
 * 			{
 *	 			Check for input error first, just to make sure
 * 				if (varAge <= constOldest)
 * 					varAgeCount[varAge/10] and increment by one
 * 				else
 * 					Display error message
 * 				Ask for another input or exit
 * 			}
 * 
 * 			** Display age group and frequency distribution **
 * 
 *			Display age group, setw(), and varAgeCount[1 through 13]
 * 
 *			** Display age group distribution bar graph **
 * 
 * 			To calculate the maximum height of the graph:
 * 			for (loopXaxis = 2; loopXaxis <= 12; loopXaxis++)
 *			{
 *				if (varAgeCount[loopXaxis] > loopHighestBar)
 *				{
 *					loopHighestBar = varAgeCount[loopXaxis];
 *				}
 *			}
 * 
 * 			And then display the graph:
 *		 	for (loopYaxis = loopHighestBar; loopYaxis >= 1; loopYaxis--)
 *			{
 *				Display the Y axis;
 * 				for (loopXaxis = 0; loopXaxis <= 12; loopXaxis++)
 * 				{
 *					if (varAgeCount[loopXaxis] >= loopYaxis) print a spaced out *
 * 					else print spaces only
 *				}
 * 			}
 *
 *			Display the bottom X axis "------"
 * 			Display the bottom labels using:
 * 			do
 * 			{
 * 				Display loopBarCountTop and then increment by 10
 * 			} while (loopBarCountTop < 120)
 * 			Display the "|" symbols using a for loop
 * 			and do
 * 			{
 *				Display loopBarCountBottom and then increment by 10
 * 			} while (loopBarCountBottom < 129)
 * 			Display the axis label and end program
 */
 
#include <iostream>
#include <iomanip>

using namespace std;
 
// Declare all the constants and variables 	
const int constOldest = 129;		// Age limit, no older than this age is allowed
int varAge,							// Individual ages go here
    loopHighestBar, 				// This helps set the bar graph size by setting it to the tallest bar
    loopXaxis,						// This constitutes the X-axis on the bar graph
    loopYaxis,						// This constitutes the Y-axis on the bar graph
    loopBarCountTop = 0,			// Define
	loopBarCountBottom = 9,			// the Age Groups
	loopRangeSymbol;				// axis labels
int varAgeCount[13];				// Age group frequency counter array

int main(int argv, char *argc[])
{
	// Program starts here
	cout << "Age Group Distribution" << endl << endl;
	cout << "Ages are in groups of 10." << endl;
	cout << "Highest possible age is 129." << endl << endl;
	cout << "*****Please enter a negative number when done.*****" << endl << endl;
	
	cout << "Please enter the first age -> ";
	cin >> varAge;
	
	// This loop checks to see if the user enters a negative number (to exit)
	while (varAge >= 0)
	{
		// Check for input error
		while (!cin)
		{
			cout << "Invalid input.  Please enter a valid age -> ";
			cin.clear();
			cin.ignore(2000,'\n');
			cin >> varAge;
		}
	
		if (varAge <= constOldest)			// Is the entered age larger than the Oldest human?
		{
			varAgeCount[varAge/10]++;		// Add one to the appropriate counter
		}
		else 								// Too old!
		{
			cout << "Age is too big - ignore." << endl;
		}
		cout << "Please enter another age (neg. to quit) -> ";
		cin >> varAge;						// Enter another age and check again ^_^
	}
	
	// This section displays the columns Age Group and Frequency
	cout << endl << "Age Group               Frequency" << endl;
	cout << "---------               ---------" << endl;
	cout << "  0 -   9" << setw(24) << varAgeCount[0] << endl;
	cout << " 10 -  19" << setw(24) << varAgeCount[1] << endl;
	cout << " 20 -  29" << setw(24) << varAgeCount[2] << endl;
	cout << " 30 -  39" << setw(24) << varAgeCount[3] << endl;
	cout << " 40 -  49" << setw(24) << varAgeCount[4] << endl;
	cout << " 50 -  59" << setw(24) << varAgeCount[5] << endl;
	cout << " 60 -  69" << setw(24) << varAgeCount[6] << endl;
	cout << " 70 -  79" << setw(24) << varAgeCount[7] << endl;
	cout << " 80 -  89" << setw(24) << varAgeCount[8] << endl;
	cout << " 90 -  99" << setw(24) << varAgeCount[9] << endl;
	cout << "100 - 109" << setw(24) << varAgeCount[10] << endl;
	cout << "110 - 119" << setw(24) << varAgeCount[11] << endl;
	cout << "120 - 129" << setw(24) << varAgeCount[12] << endl;
	cout << "Smack any key to continue ...";
	cin.ignore();
	cin.get();			// Pause it (a platform-agnostic way of doing it)
	cout << endl << endl;
	
	// This is the part about the bar graph
	cout << "Age Distribution Bar Graph" << endl << endl;
	
	loopHighestBar = varAgeCount[1];						// Initialize this variable
	
	for (loopXaxis = 2; loopXaxis <= 12; loopXaxis++)					// Calculate the tallest
	{
		if (varAgeCount[loopXaxis] > loopHighestBar)					// bar and set it to
		{
			loopHighestBar = varAgeCount[loopXaxis];					// this variable
		}
	}
	
	for (loopYaxis = loopHighestBar; loopYaxis >= 1; loopYaxis--)	// Creates the Y axis
	{
		cout << endl << setw(4) << loopYaxis << " |";				// Display the Y axis

		for (loopXaxis = 0; loopXaxis <= 12; loopXaxis++)			// Loop to create
 		{
			if (varAgeCount[loopXaxis] >= loopYaxis)				// the asterisks to
			{
				cout << "   *"; 								// display the bars
 			}
 			else
 			{
				cout << "    ";
			}
		}
 	}
 	
	cout << endl << "     +----------------------------------------------------" << endl;		// Draw the X axis
	cout << "      ";				// Position the cursor for the next operation
			
	do 											// Display the 0 range
	{
		cout << setw(4) << loopBarCountTop;
		loopBarCountTop = loopBarCountTop + 10;
	}
	while (loopBarCountTop <= 120);
	
	cout << endl << "      ";		// Position the cursor for the next operation
	
	for (loopRangeSymbol = 0; loopRangeSymbol < 13; loopRangeSymbol++)		// Display the | symbol
	{
		cout << setw(4) << "|";
	}
	
	cout << endl << "      ";		// Position the cursor for the next operation
	
	do 											// Display the 9 range
	{
		cout << setw(4) << loopBarCountBottom;
		loopBarCountBottom = loopBarCountBottom + 10;
	}
	while (loopBarCountBottom <= 129);
	
	cout << endl << endl << "                          Age Groups" << endl;
	 	
 	return 0;
}				// Finito