package trak.parentheses;



import trak.datastructures.TrakStack;

/**
 * Class to check whether parentheses in input are valid
 *
 */

public class CheckParentheses {
    TrakStack stack = new TrakStack();

    // IMPLEMENT THIS CLASS

    public boolean check(String input) {
        for (int i = 0; i < input.length(); i++) {
            char current = input.charAt(i);
            if (current == '(' || current == '[' || current == '{') {
                this.stack.push(current);
            }
                if (current == ')') {
                    if (this.stack.isEmpty()) {
                        return false;
                    } if (this.stack.top().equals('(')) {
                        this.stack.pop();

                    }
                }else if(current == ']') {
                        if (this.stack.isEmpty()) {
                            return false;
                        } if (this.stack.top().equals('[')) {
                            this.stack.pop();
                        }

        }else if (current == '}') {
            if (this.stack.isEmpty()) {
                return false;
            } if (this.stack.top().equals('{')) {
                this.stack.pop();
        }




    }
    }if (this.stack.isEmpty()) {
        return true;
    }return false;
    }
}