// File: bits.cxx
// Written by: Michael Main (main@colorado.edu)
// The purpose of this program is the print the bit patterns for
// letters and small numbers (from 0 to 255).

#include <cctype>
#include <iomanip>
#include <iostream>
using namespace std;

// void binary_pattern(int i)
// This function prints the least significant 8 bits of i,
// with the least significant one printed last.  It then
// prints a space and prints the same thing in base 16.
void binary_pattern(int x)
{
    int mask;

    // Throw away any bits beyond the lower 8:
    x &= 0xFF;
    
    // Prints the least significant 8 bits
    for (mask = 128; mask > 0; mask >>= 1)
    {
	cout << ((x & mask) ? '1' : '0');
    }

    // Prints the same thing in base 16 (hexadecimal):
    if (x < 16) cout << " 0";
    else cout << " ";
    cout << setbase(16) << x;
}

int main( )
{
    int number;  // A number typed by the user
    char letter; // A letter typed by the user
    
    cout << "Please type numbers from 0-255 and letters." << endl;
    cout << "Press ctrl-c to end the program." << endl;
    while (true)
    {
	if (isdigit(cin.peek( )))
	{
	    cin >> number;
	    if (0 <= number && number <= 255)
	    {
		cout << setw(10) << number << ": ";
		binary_pattern(number);
		cout << endl;
	    }
	}
	else if (isalpha(cin.peek( )))
	{
	    cin >> letter;
	    cout << setw(10) << letter << ": ";
	    binary_pattern(letter);
	    cout << endl;
	}
	else
	{
	    cin.ignore( );
	}
    }
    return 0;
}