public struct ServerConfig

    {

        /// <summary>

        /// 初始权重

        /// </summary>

        public int Weight { get; set; }

        /// <summary>

        /// 当前权重

        /// </summary>

        public int Current { get; set; }

        /// <summary>

        /// 服务名称

        /// </summary>

        public string Name { get; set; }

    }

        public static int NextServerIndex(ServerConfig[] ss)

        {

            int index = -1;

            int total = 0;

            int size = ss.Count();    

            for (int i = 0; i < size; i++)

            {

                ss[i].Current += ss[i].Weight;

                total += ss[i].Weight;

                if (index == -1 || ss[index].Current < ss[i].Current)

                {

                    index = i;

                }

            }

            ss[index].Current -= total;

            return index;

        }

        static void Main(string[] args)

        {

            var sv = new ServerConfig[] {

                new ServerConfig{ Name="A",Weight=4},

                new ServerConfig{ Name="B",Weight=2},

                new ServerConfig{ Name="C",Weight=1}

            };

            int index = 0;

            int sum = sv.Sum(m => m.Weight);

            for (int i = 0; i < sum; i++)

            {

                index = NextServerIndex(sv);

                Console.WriteLine("{0} {1}", sv[index].Name, sv[index].Weight);

            }

            Console.Read();

        }