153. Redundant Brackets
Challenge1000 ms256 MBSolved by 0%
An expression contains redundant brackets when some pair surrounds nothing
that needs bracketing — either an empty pair, or a pair with no operator directly inside
it. So (a+b) is fine, but ((a+b)) and (a) are both redundant.
Read one expression made of lowercase letters, the operators + - * /, and brackets, and
print Yes if it contains a redundant pair or No if it does not.
The brackets are always balanced.
Constraints - The line has between 1 and 100000 characters. - Only lowercase letters, `+ - * /`, and `(` `)`.
Input
A single line containing lowercase letters, the operators + - * /, and balanced brackets.
Output
Print exactly one word: Yes or No.
Input((a+b))
OutputYes
Notehas an outer pair wrapping an already-bracketed expression
Input(a+b)
OutputNo
Notehas a bracket pair that does real work
Hints
Four rungs, in order. The last two open once you have submitted an attempt — a wrong one counts.
Hint 1Where to start
Hint 2The approachOpen hint 1 first — this one carries on from it.
Hint 3PseudocodeOpen hint 2 first — this one carries on from it.
Hint 4Full solutionOpen hint 3 first — this one carries on from it.