### xsltxdy's blog

By xsltxdy, history, 5 weeks ago,

here are some laws about legal bracket strings:

• an empty string is a legal bracket string
• if A is a legal bracket string, so (A) is a legal bracket string
• if A is a legal bracket string and B is a legal bracket string, so AB is a legal bracket string

And I want to know that what is the minimum edits that letting a bracket string to be legal?

Thank you so much!

• +8

 » 5 weeks ago, # | ← Rev. 5 →   +3 Is there a place to submit, I have this greedy idea cnt = 0 diff = 0 /// count('(') - count(')') For each char &c in string in normal order -- if (c = '(') ++diff else --diff -- if (diff < 0) ---- c = '(' ---- diff += 2 ---- cnt += 1 diff = 0 /// count(')') - count('(') For each char &c in string in reverse order -- if (c = ')') ++diff else --diff -- if (diff < 0) ---- c = ')' ---- diff += 2 ---- cnt += 1 out << cnt 
•  » » 5 weeks ago, # ^ |   0 thank you for helping me and i am soooooooo sorry that i didn't log into this account yesterday and i did not see this answerand i really want to say thank you for solving a kind of strange question :)i will study hard tomorrow :)
•  » » » 5 weeks ago, # ^ | ← Rev. 2 →   0 Sometimes ad-hoc/implementation problems takes time to solve whatever your level is. It is ok bro