Data-Abs-In-class-Exercise/Solution.java at main · mtyree-trin/Data-Abs-In-class-Exercise · GitHub

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import java.util.Stack;

class Solution {
    public boolean isValid(String s) {
        if (s.length() <= 1){
            return false;
        }

        Stack<Character> stack = new Stack<>();

        for (int i = 0; i < s.length(); i++) {
            char current = s.charAt(i);


            if (current == '(' || current == '[' || current == '{') {
                stack.push(current);
            } else {

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

                char top = stack.pop();

                if (current == ')' && top != '(') {
                    return false;
                }
                if (current == '}' && top != '{') {
                    return false;
                }
                if (current == ']' && top != '[') {
                    return false;
                }
            }
        }

        return stack.isEmpty();
}
}