CF1202E You Are Given Some Strings...
Description
You are given a string $ t $ and $ n $ strings $ s_1, s_2, \dots, s_n $ . All strings consist of lowercase Latin letters.
Let $ f(t, s) $ be the number of occurences of string $ s $ in string $ t $ . For example, $ f('\text{aaabacaa}', '\text{aa}') = 3 $ , and $ f('\text{ababa}', '\text{aba}') = 2 $ .
Calculate the value of $ \sum\limits_{i=1}^{n} \sum\limits_{j=1}^{n} f(t, s_i + s_j) $ , where $ s + t $ is the concatenation of strings $ s $ and $ t $ . Note that if there are two pairs $ i_1 $ , $ j_1 $ and $ i_2 $ , $ j_2 $ such that $ s_{i_1} + s_{j_1} = s_{i_2} + s_{j_2} $ , you should include both $ f(t, s_{i_1} + s_{j_1}) $ and $ f(t, s_{i_2} + s_{j_2}) $ in answer.
Input Format
The first line contains string $ t $ ( $ 1 \le |t| \le 2 \cdot 10^5 $ ).
The second line contains integer $ n $ ( $ 1 \le n \le 2 \cdot 10^5 $ ).
Each of next $ n $ lines contains string $ s_i $ ( $ 1 \le |s_i| \le 2 \cdot 10^5 $ ).
It is guaranteed that $ \sum\limits_{i=1}^{n} |s_i| \le 2 \cdot 10^5 $ . All strings consist of lowercase English letters.
Output Format
Print one integer — the value of $ \sum\limits_{i=1}^{n} \sum\limits_{j=1}^{n} f(t, s_i + s_j) $ .