Solution: Remove Invalid Parentheses
Explore the backtracking technique to remove invalid parentheses from a string. Understand how to count and remove unmatched parentheses, recursively build valid combinations, and return all unique valid expressions. This lesson helps you apply a systematic approach to solve parentheses validation problems efficiently.
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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:
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