using System;
class BinToDec
{
static void Main(string[] args)
{
string binary = "101";
Console.WriteLine(BinaryToDecimal(binary)); // will return 5
}
private static long BinaryToDecimal(string binary)
{
long decimalNum = 0;
for (int i = binary.Length - 1, pow = 0; i >= 0; i--, pow++)
{
decimalNum += int.Parse(binary[i].ToString()) * (long)Math.Pow(2, pow);
}
return decimalNum;
}
}