C# 高精度求幂 poj1001

高精度求幂

public static char[] exponentiation(string a,int r)

        {

            char[] aa = new char[1];

            string b = "";

            string c = a;

            for (int i = 0; i < r-1; i++)

            {

                aa = acm.Quadrature(c, a);

                b = "";

                foreach (var item in aa)

                {

                    b += item;

                }

                c = b;

            }

            return aa;

        }