摘要：
A string is finite sequence of characters over a non empty finite set $\sum$. In this problem, $\sum$ is the set of lowercase letters. Substring, also 阅读全文
摘要：
A string is finite sequence of characters over a non empty finite set $\sum$. In this problem, $\sum$ is the set of lowercase letters. Substring, also 阅读全文
摘要：
Little Daniel loves to play with strings! He always finds different ways to have fun with strings! Knowing that, his friend Kinan decided to test his 阅读全文
摘要：
You are given a string $S$ which consists of 250000 lowercase latin letters at most. We define $F(x)$ as the maximal number of times that some string 阅读全文