Search⌘ K
AI Features

Solution: Remove Invalid Parentheses

Explore a backtracking approach to remove invalid parentheses from a given string. Understand how to count and remove minimum unmatched parentheses and generate all unique valid strings by recursively considering each character. This lesson helps you implement a solution that handles string balancing efficiently.

Statement

You are given a string, s, that contains:

  • Lowercase English letters

  • Opening '(' and closing ')' parentheses

A string is considered valid if:

  1. All opening parentheses '(' are closed properly by a matching ')'.

  2. The parentheses are in the correct order and nesting.

  3. 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:

  • 1 ...