How to check if a String is balanced?

Question

I want to test if an input String is balanced. It would be balanced if there is a matching opening and closing parenthesis, bracket or brace.

example:
{} bal         


        

Answer 1

corresponding Hackrrank link: https://www.hackerrank.com/challenges/balanced-brackets/problem

import java.util.Stack;

class BalancedParenthesis {
    static String isBalanced(String s) {
        return isBalanced(s.toCharArray());
    }

    private static String isBalanced(final char[] chars) {
        final Stack stack = new Stack<>();
        for (char eachChar : chars) {
            if (eachChar == '{' || eachChar == '[' || eachChar == '(') {
                stack.push(eachChar);
            } else {
                if (stack.isEmpty()) {
                    return "NO";
                }
                if (correspondingCloseBracket(stack.peek()) != eachChar) {
                    return "NO";
                }
                stack.pop();
            }
        }
        return stack.isEmpty() ? "YES" : "NO";
    }

    private static char correspondingCloseBracket(final char eachChar) {
        if (eachChar == '{') {
            return '}';
        }
        if (eachChar == '[') {
            return ']';
        }
        return ')';
    }
}