leetcode系列---Two Sum C#code

        /// <summary>
        /// 方法一：双循环
        /// </summary>
        /// <param name="array"></param>
        /// <param name="target"></param>
        /// <returns></returns>
        public static List<int[]> twoSum(int[] array, int target)
        {
            //int[] result;
            List<int[]> result = new List<int[]>();
            for (int i = 0; i < array.Count(); i++)
            {
                for (int j = i + 1; j < array.Count(); j++)
                {
                    if (array[i] + array[j] == target && i != j)
                    {
                        int[] aa = { i, j };
                        result.Add(aa);
                    }
                }
            }
            return result;
        }
        /// <summary>
        /// 方法二：单循环 
        /// </summary>
        /// <param name="array"></param>
        /// <param name="target"></param>
        /// <returns></returns>
        public static List<int[]> twoSum2(int[] array, int target)
        {
            List<int[]> result = new List<int[]>();
            for (int i = 0; i < array.Count(); i++)
            {
                var x = array.Select((a, index) => new { a, index }).Where(a => a.a == (target - array[i]));
                if (x.ToList().Count != 0 && i != x.ToList()[0].index)
                {
                    int[] aa = { i, x.ToList()[0].index };
                    var y=result.Where(a => a[0] == x.ToList()[0].index && a[1] == i);
                    if (y.ToList().Count == 0)
                        result.Add(aa);
                }
            }
            return result;
        }

　　控制台展示：

 static void Main(string[] args)
        {
            Console.WriteLine("请输入数组：");

            string ss = Console.ReadLine();
            int length = ss.Length;
            int[] arry = new int[length];
            for (int i = 0; i < length; i++)
            {
                string s = ss.Substring(i, 1);
                arry[i] = Convert.ToInt32(s);
            }
            Console.WriteLine("请输入目标值：");
            int target = Convert.ToInt32(Console.ReadLine());
            List<int[]> result = twoSum2(arry, target);
            foreach (int[] ar in result)
            {
                foreach (int i in ar)
                {
                    Console.Write(i);
                }
            }
            Console.ReadLine();
        }