Why does Valid Parentheses use a stack?

Question

Why does Valid Parentheses use a stack?

Option A — Correct answer

Nested brackets close in reverse order

Option B

The string is sorted

Option C

Brackets are counted by frequency only

Option D

The answer needs binary search

Explanation

Nested brackets must close in reverse order, which is last-in-first-out behavior.

Valid Parentheses - Stack matching Pattern Practice Quiz