#Lutece1643. 括号匹配
括号匹配
Migrated from Lutece 1643 括号匹配
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Description
给你一个仅包含和的括号序列,你需要把每个替换为或
请问有多少种替换方法,使得最后的括号序列是一个合法括号序列?
答案可能很大,请输出模后的答案
Input
输入一个字符串,长度不超过
Output
输出模后方案数
Samples
(???
2
Resources
missever