Ejemplo n.º 1
0
        /// <summary>
        /// Calculates a Subtraction of a two ALong absolute values, a.k.a "School" method.
        /// </summary>
        /// <param name="num1">Minuend</param>
        /// <param name="num2">Subtrahend</param>
        /// <returns>ALong instance representing a difference between absolute values of minuend and subtrahend.</returns>
        private static ALong AbsSub(ALong num1, ALong num2)
        {
            if (num1 == num2)
            {
                return(new ALong(0));
            }
            var big   = AMath.Max(Abs(num1), Abs(num2));
            var small = AMath.Min(Abs(num1), Abs(num2));

            var result = String.Empty;
            int carry  = 0;

            for (int i = 0; i < big.Length(); i++)
            {
                var n1 = big.GetRNumAtIndex(i);
                var n2 = small.GetRNumAtIndex(i);
                var ns = n1 - carry;
                carry = 0;
                if (ns < n2)
                {
                    ns += 10; carry = 1;
                }
                ns     = ns - n2;
                result = ns.ToString() + result;
            }

            return(new ALong(result));
        }
Ejemplo n.º 2
0
        /// <summary>
        /// Converts string representation of a number in a given base to ALong number.
        /// Extension does not check if you provide invalid numbers, e.g. '1010102' in base 2 - you will just get incorrect answer.
        /// </summary>
        /// <param name="number">String representation of a number</param>
        /// <param name="aBase">Base number is presented in</param>
        /// <param name="sym">String of symbols used to represent a number.</param>
        /// <returns>ALong number</returns>
        public static ALong FromArbitraryBase(this string number, int aBase, string sym = null)
        {
            if (String.IsNullOrEmpty(sym))
            {
                sym = GetSymbols(aBase);
            }
            if (aBase < 37)
            {
                number = number.ToLower();
            }                                              // Ignore case if base <= 36

            var r    = number.Reverse();
            var resp = new ALong(0);
            var i    = 0;

            foreach (var c in r)
            {
                var index = sym.IndexOf(c);
                resp = resp + AMath.Pow(new ALong(aBase), i) * index;
                i++;
            }
            return(resp);
        }