682. 棒球比赛

class Solution {
    public int calPoints(String[] ops) {
        List<Integer> iList = new ArrayList<Integer>();

        for (String s : ops) {
            switch (s.charAt(0)) {
                case '+':
                    iList.add(iList.get(iList.size() - 1) + iList.get(iList.size() - 2));
                    break;
                case 'D':
                    iList.add(iList.get(iList.size() - 1) * 2);
                    break;
                case 'C':
                    iList.remove(iList.size() - 1);
                    break;
                default:
                    iList.add(Integer.parseInt(s));
                    break;
            }
        }

        int sum = 0;

        for (int i : iList) {
            sum += i;
        }

        return sum;
    }
}