Basic Recursion, Check Balanced Parenthesis

Posted by pws5068 on Stack Overflow See other posts from Stack Overflow or by pws5068
Published on 2010-04-26T03:41:21Z Indexed on 2010/04/26 3:43 UTC
Read the original article Hit count: 451

Filed under:

recursion

|

homework

|

nested

|

stack

|

recursive

Greetings all,

I've written software in the past that uses a stack to check for balanced equations, but now I'm asked to write a similar algorithm recursively to check for properly nested brackets and parenthesis.

Good examples: () [] () ([]()[])

Bad examples: ( (] ([)]

Suppose my function is called: isBalanced.

Should each pass evaluate a smaller substring (until reaching a base case of 2 left)? Or, should I always evaluate the full string and move indices inward?

© Stack Overflow or respective owner

Related posts about recursion

tail recursion vs. forward recursion

as seen on Stack Overflow - Search for 'Stack Overflow'
Can someone give me the difference between these two kinds recursions and example? specifically in ocaml. Thanks >>> More
Are there advantages for using recursion over iteration - other than sometimes readability and elegance?

as seen on Programmers - Search for 'Programmers'
I am about to make two assumptions. Please correct me if they're wrong: There isn't a recursive algorithm without an iterative equivalent. Iteration is always cheaper performance-wise than recursion (at least in general purpose languages such as Java, C++, Python etc.). If it's true that recursion… >>> More
Python recursive function error: "maximum recursion depth exceeded"

as seen on Stack Overflow - Search for 'Stack Overflow'
I solved Problem 10 of Project Euler with the following code, which works through brute force: def isPrime(n): for x in range(2, int(n**0.5)+1): if n % x == 0: return False return True def primeList(n): primes = [] for i in range(2,n): if isPrime(i): … >>> More
Dynamic Programming Recursion and a sprinkle of Memoization

as seen on Stack Overflow - Search for 'Stack Overflow'
I have this massive array of ints from 0-4 in this triangle. I am trying to learn dynamic programming with Ruby and would like some assistance in calculating the number of paths in the triangle that meet three criterion: You must start at one of the zero points in the row with 70 elements. Your… >>> More
How does the recursion here work?

as seen on Stack Overflow - Search for 'Stack Overflow'
code 1: public static int fibonacci (int n){ if (n == 0 || n == 1) { return 1; } else { return fibonacci (n-1) + fibonacci (n-2); } } how can you use fibonacci if you haven't gotten done explaining what it is yet? I've been able to understand… >>> More

Related posts about homework

parsing a list and producing a structure of that

as seen on Stack Overflow - Search for 'Stack Overflow'
;; structure representing homework points ;; nr: number - the number of the homework ;; points: number - the number of points reached (define-struct homework (nr points)) ;; parse-homework: (list of number pairs) -> (list of homework) ;; The procedure takes a list of number pairs and produces… >>> More
Scheme homework help

as seen on Stack Overflow - Search for 'Stack Overflow'
Okay so I have started a new language in class. We are learning Scheme and i'm not sure on how to do it. When I say learning a new language, I mean thrown a homework and told to figure it out. A couple of them have got me stumped. My first problem is: Write a Scheme function that returns true (the… >>> More
Unix [Homework]: Get a list of /home/user/ directories in /etc/passwd

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm very new to Unix, and currently taking a class learning the basics of the system and its commands. I'm looking for a single command line to list off all of the user home directories in alphabetical order from the /etc/passwd directory. This applies only to the home directories, and not the contents… >>> More
[Homework] Online programming editor

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, For a school project i need to write or use a online programming editor. It is a part of a bigger project. I thought of a java application, php/html/javascript or flash. I have a couple of things i could do: Find a good working application and edit it so it works with the rest of the project Find… >>> More
sequential search homework question

as seen on Stack Overflow - Search for 'Stack Overflow'
Consider a disk file containing 100 records a. How many comparisons would be required on the average to find a record using sequential search, if the record is known to be in the file? I figured out that this is 100/2 = 50. b. If the record has a 68% probability of being in the file, how many comparisons… >>> More