Daily LeetCode – day0072 0856. Score of Parentheses

// 0856. Score of Parentheses
class Solution {
    public int scoreOfParentheses(String s) {
        char[] parentheses = s.toCharArray();
        int[] stack = new int[25];
        int pointer = -1;
        for (char c : parentheses) {
            if (c == '(') {
                ++pointer;
                stack[pointer] = 0;
            } else if (stack[pointer] == 0) {
                --pointer;
                if (pointer == -1 || stack[pointer] == 0) {
                    ++pointer;
                    stack[pointer] = 1;
                } else {
                    stack[pointer] = stack[pointer] + 1;
                }
            } else {
                int top = stack[pointer];
                --pointer;
                --pointer;
                if (pointer == -1 || stack[pointer] == 0) {
                    ++pointer;
                    stack[pointer] = top * 2;
                } else {
                    top = top * 2 + stack[pointer];
                    stack[pointer] = top;
                }
            }
        }
        return stack[0];
    }
}

学习笔记：
这是一道栈的题目，但是用stack就需要1ms。
刚好今天比较空闲，就再尝试了手写数组模拟的栈，这样只需要0ms。