//Rather use this, As this can perfectly handle the condition where closing brackets are more than opening brackets

package Stacks;

import java.util.Scanner;
import java.util.Stack;

/**
*

• The nested brackets problem is a problem that determines if a sequence of
• brackets are properly nested. A sequence of brackets s is considered properly
• nested if any of the following conditions are true: - s is empty - s has the
• form (U) or [U] or {U} where U is a properly nested string - s has the form
• VW where V and W are properly nested strings For example, the string
• "()()[()]" is properly nested but "[(()]" is not. The function called
• is_balanced takes as input a string S which is a sequence of brackets and
• returns true if S is nested and false otherwise.
• @author akshay sharma
• @Date: 2017-10-17
• @author khalil2535

*/
class BalancedBrackets {

/**
 *
 * @param s
 * @return
 */
static boolean is_balanced(String s) {
    Stack<Character> bracketsStack = new Stack<>();
    char[] text = s.toCharArray();
    for (char x : text) {
        switch (x) {
            case '{':
            case '<':
            case '(':
            case '[':
                bracketsStack.push(x);
                break;
            case '}':
                if (bracketsStack.peek() == '{') {
                    bracketsStack.pop();
                    break;
                } else {
                    return false;
                }
            case '>':
                if (bracketsStack.peek() == '<') {
                    bracketsStack.pop();
                    break;
                } else {
                    return false;
                }
            case ')':
                if (bracketsStack.peek() == '(') {
                    bracketsStack.pop();
                    break;
                } else {
                    return false;
                }
            case ']':
                if (bracketsStack.peek() == '[') {
                    bracketsStack.pop();
                    break;
                } else {
                    return false;
                }
        }
    }
    return bracketsStack.empty();
}

/**
 *
 * @param args
 * @TODO remove main method and Test using JUnit or other methodology
 */
public static void main(String args[]) {
    try (Scanner in = new Scanner(System.in)) {
        System.out.println("Enter sequence of brackets: ");
        String s = in.nextLine();
		try {
			if (is_balanced(s)) {
				System.out.println(s + " is balanced");
			} else {
				System.out.println(s + " ain't balanced");
			}
		} catch (Exception e) {
			System.out.println(s + " isn't balanced");
		}
    }
}

}