Valid Parentheses

Difficulty: Easy · Topic: Stacks & queues

Given a string s containing only (), [] and {}, return True if every bracket is closed by the matching type in the correct order, else False.

Examples

is_valid("()")
→ true

is_valid("()[]{}")
→ true

is_valid("(]")
→ false

'(' is closed by ']'.

Target complexity: time O(n), space O(n)

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