Description
4. Valid Parentheses

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

An input string is valid if:

  • Open brackets must be closed by the same type of brackets.
  • Open brackets must be closed in the correct order.
  • Every close bracket has a corresponding open bracket of the same type.

Example 1: 

Input:  s = "()"
Output:true

Example 2: 

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

Example 3: 

Input:  s = "(]"
Output:false

Example 4: 

Input:  s = "([)]"
Output:false
Constraints:
  • 1 <= s.length <= 104
  • s consists of parentheses only '()[]{}'.
Testcases
Case 1
Case 2
Case 3
Case 4

Input:

s = "()"

Output:

true