Problem: Valid Parentheses
Explore how to determine if a string of parentheses and brackets is valid by using a stack in Java. Learn the step-by-step technique to track opening and closing brackets, ensuring proper nesting and matching. This lesson helps you implement an efficient O(n) time solution using last-in, first-out logic.
We'll cover the following...
Statement
Given a string s consisting only of the characters '(', ')', '{', '}', '[', and ']', determine whether the string represents a valid sequence of brackets.
A string is considered valid if all of the following conditions are satisfied:
Every opening bracket is closed by a bracket of the same type.
Brackets are closed in the correct (properly nested) order.
Every closing bracket has a matching opening bracket of the same type.
Return True if the string is valid, and False otherwise.
Constraints:
...