Valid Brackets

You are given a string s of brackets (, ), [, ], { and }.

Return true if the string is valid.

A string of brackets is valid when:

• every opening bracket is closed by a bracket of the same type
• open brackets are closed in the correct order.
• every closing bracket closes a bracket that was opened before it

Example 1:

Input:  s = "{[()]}"
Output: true

Example 2:

Input:  s = "([)]"
Output: false

Example 3:

Input:  s = "())"
Output: false

Constraints:

• 1 <= length of s <= 10^4
• s consists of the characters (, ), [, ], { and }