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Leetcode 921. Minimum Add to Make Parentheses Valid

Given a string of '(' and ')', return the minimum number of parentheses insertions needed to make the string valid. This is solved greedily by scanning once and counting unmatched closing parentheses and leftover opening parentheses that require insertions.

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Company

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Early November, 2025

Meta

Manager

Late October, 2025

Meta

Senior

Early June, 2025

Meta

Senior

Only dealing with parenthesis input

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