How should I practice Valid Parentheses?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Meta phone screen problems in FastPrep.

Is Valid Parentheses associated with Meta?

FastPrep tags this as a Meta phone screen coding practice problem when the problem catalog has that company and stage context.

Meta● EasyINTERNPHONE SCREEN

Given a nonempty string s containing only (, ), [, ], {, and }, determine whether it is valid.

A string is valid when:

Return true when s is valid; otherwise, return false.

isValidParentheses(s: String) → boolean

s = "()"return = true

The opening parenthesis is closed by the matching closing parenthesis.

s = "()[]{}"return = true

Each opening bracket closes with the same type, and no bracket closes out of order.

s = "([)]"return = false

The closing parenthesis appears before the nested square bracket is closed.

s = "([])"return = true

The square brackets close first, followed by the surrounding parentheses.