Solution: Remove Invalid Parentheses
Explore how to use backtracking to remove invalid parentheses from a string by searching all valid combinations with minimal removals. Learn the process of counting unmatched parentheses and recursively building balanced expressions. Understand the complexity of the solution to confidently apply this pattern in coding interviews.
We'll cover the following...
Statement
You are given a string, s, that contains:
Lowercase English letters
Opening
'('and closing')'parentheses
A string is considered valid if:
All opening parentheses
'('are closed properly by a matching')'.The parentheses are in the correct order and nesting.
Letters can appear anywhere and do not affect validity.
Return all possible valid strings that can be formed by removing the minimum number of invalid parentheses. The answer must be a list of unique strings, in any order.
Constraints:
...