16_BintoHex.java

public class BintoHex
{
	public static int digitToValue(char c) 
	{
		if (c >= '0' && c <= '9') 
		{
			return c - '0';
		} 
		else if (c >= 'A' && c <= 'F') 
		{
			return 10 + c - 'A';
		} 
		else if (c >= 'a' && c <= 'f') 
		{
			return 10 + c - 'a';
		}
		return -1;
	}
	
	public static int convertFromBase(String number, int base) 
	{
		if (base < 2 || (base > 10 && base != 16)) 
			return -1;
		int value = 0;
		for (int i = number.length() - 1; i >= 0; i--) 
		{
			int digit = digitToValue(number.charAt(i));
			if (digit < 0 || digit >= base) 
			{
				return -1;
			}
			int exp = number.length() - 1 - i;
			value += digit * Math.pow(base, exp);
		}
		return value;
	}
	
	public static boolean compareBinToHex(String binary, String hex) 
	{
		int n1 = convertFromBase(binary, 2);
		int n2 = convertFromBase(hex, 16);
		if (n1 < 0 || n2 < 0) 
		{
			return false;
		}
		return n1 == n2;
	}	
	public static void main(String[] args)
	{
		
		System.out.println(compareBinToHex("111001011", "1CB"));
	} 
}