Basic Recursion, Check Balanced Parenthesis

Question

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 neste

Answer 1

 public static boolean isBalanced(String str) {
    if (str.length() == 0) {
        return true;
    }
    if (str.contains("()")) {
        return isBalanced(str.replaceFirst("\\(\\)", ""));
    }

    if (str.contains("[]")) {
        return isBalanced(str.replaceFirst("\\[\\]", ""));
    }
    if (str.contains("{}")) {
        return isBalanced(str.replaceFirst("\\{\\}", ""));
    } else {
        return false;
    }
}