一道面试题

 面试题：

求字符s1 = "lookyou";和s2 = "likeyou";最长字符交集。输出：“you”
用一个函数实现；

C#实现：

        public string Find()
        {
            string s1 = "lookyou";
            string s2 = "likeyou";
            List<string> lst2 = new List<string>();
            int k2 = s2.Length;
            for (int j = 0; j < k2; j++)
            {
                string tempS = s2.Substring(j);
                for (int i = 0; i < tempS.Length; i++)
                {
                    lst2.Add(tempS.Substring(0, i + 1));
                }
            }

            string tempS1 = "";
            for (int i = 0; i < lst2.Count; i++)
            {
                string temp2 = lst2[i];
                if (s1.IndexOf(temp2) > -1)
                {
                    if (temp2.Length > tempS1.Length)
                    {
                        tempS1 = temp2;
                    }
                }
            }
            return tempS1;
        }