.写一个程序，能够读一行 string, 然后打出 最长的 那个 substring p （就是最长的小分句），并且那个小分句要求出现超过一次的。如果有超过1个那样的substring, 只要打出那个字母顺序排后面的-. To write a program that can read his string, and then played the longest substring p (is the longest small clause), and request that a small clause appears more than once. If there is more than one kind of substring, as long as the shot was behind schedule in alphabetical order