#include <iostream>
#include <string>
using namespace std;
 
// function returns binary string... even with preceding zeros binary number is still correct.
 
string convertDecimalToBinary(int value);
 
int main()
{	
	int x = 0;
	string s2("NEGATIVE NUMBER EXITING");
 
	cout << "Enter a decimal number (max 524288): ";
	cin >> x;
	cout << endl;
	if(convertDecimalToBinary(x) != s2)
	{
		cout << "The number in binary is: " 
			<< convertDecimalToBinary(x)<< endl; // call function...
	}
	else
	{
		cout << s2 << endl;
	}
 
	system("pause");
 
	return 0;
}
 
string convertDecimalToBinary(int value)
{
 
	const int AMOUNT = 20;
 
	int one[AMOUNT];	
    int num_digits(0);
	int iTemp(0);
	string s2("NEGATIVE NUMBER EXITING");
 
	iTemp = value;
 
    if(iTemp < 0)
	{
	  return s2;
	}
 
    while(iTemp > 0) 
    {
	   num_digits++;
	   iTemp /= 2;
    }
 
	for(int i = num_digits; i > 0; i--)
	{
		one[i] = value % 2;
		value = value / 2;
	}
 
	string s1; 
 
	for (int i = 0; i <= num_digits; i++)
		{
			if (one[i] == 1)
			{
				s1.append("1");
			}
			else if (one[i] == 0)
			{
				s1.append("0");
			}
		}
 
	return s1;
}