#P10960. [2015杭电多校]Easy Sequence
[2015杭电多校]Easy Sequence
Easy Sequence
Problem Description
soda has a string containing only two characters -- '(' and ')'. For every character in the string, soda wants to know the number of valid substrings which contain that character. Note: An empty string is valid. If is valid, is valid. If are valid, is valid.
Input
There are multiple test cases. The first line of input contains an integer , indicating the number of test cases. For each test case: A string consisting of '(' or ')' .
Output
For each test case, output an integer $m =\displaystyle \sum_{i = 1}^{|s|} (i\cdot ans_i \text{ mod } 1000000007)$, where is the number of valid substrings which contain -th character.
Sample Input
2
()()
((()))
Sample Output
20
42
Hint
For the second case, , then $m=1 \cdot 1 + 2 \cdot 2 + 3 \cdot 3 + 4 \cdot 3 + 5 \cdot 2 + 6 \cdot 1 = 42$
Author
zimpha@zju
Source
2015 Multi-University Training Contest 6