Valid Closers

How to run

javac ValidClosers.java 
java ValidClosers

Discussion

• Runtime: O(n)
• Space: O(n)

The solution is a stack implementation, the stack must follow these rules:

• openers get pushed to the stack
• openers will be poped from the stack if the closers meet the following conditions:
  • stack is not empty
  • The first element on the stack is in openers
  • The closers must close the openers popped from the stack
• stack must be empty after the string has been processed