could not think of any process for the problem
Brackets All Over
what does modulo 10^9+7 means?
Hey @RULEREMPIRES
Just what you have to do is think of a recursive approach first.
Actually the question says that you have to generate the string of size n given m is the length of given string
Where m<=n
Now you have to generate a bracket string which is balanced
By adding a prefix and suffix string to given string s
Now the prefix string should have opening brackets greater than closing brackets, because the string should be overall be balanced.
For example if you are given s = “))” and n = 6(m = 2 obviously) then you can generate following pairs of a and b to make a+s+b a valid sequence:
“()((” “))” “” // Remeber a and b can be blank also.
“((” “))” “()”
“(((” “))” “)”
“(()(” “))” “”
“((()” “))” “”
Hence, the ans for this testcase is 5. If there is no possible combination then print -1.