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;
         }