Valid or Well Formed Parentheses | Part – 1
Objective: You have been asked to Write an algorithm to find Whether Given the Sequence of parentheses are well formed. This question was asked in the Amazon Interview.
Input: A String contains a sequence of parentheses
Output: true or false on whether parentheses are well formed or not
Approach:
- Idea is to have two counters, one for open parentheses ‘{‘ and one for close ‘}’
- Read one character at a time and increment one of the counters
- If any given point of time count of close parentheses is greater than the open one, return false
- If at the end both counters are equal, return true
Example: { { } { } } – Well formed
{ { } { = Not well formed
Complete Code:
Output:
Is {{{{}}}}{}{}{}{}{}{}{}{}{}{}{{{}}} well formed ??? :true
Is {{{{}}}}{}{}{}{{}{}{}{}{}{}{}{{{}}} well formed ??? :false
Is {}{ well formed ??? :false
Is }{ well formed ??? :false
Is {{{{{{{{}}}}}}}} well formed ??? :true
