LeetCode682-棒球比赛

传送门
水题，一眼栈

class Solution {
public:
    int calPoints(vector<string>& ops) {
        stack<int> stk;

        for (auto el : ops) {
            if (el[0] == 'C') {
                if (!stk.empty()) {
                    stk.pop();
                }
            } else if (el[0] == 'D') {
                int score = stk.top();
                stk.push(score * 2);
            } else if (el[0] == '+') {
                int score1 = stk.top();stk.pop();
                int score2 = stk.top();stk.pop();
                int newScore = score1 + score2;

                stk.push(score2);
                stk.push(score1);
                stk.push(newScore);

                // cout << score1 << "+" << score2 << endl;
                // cout << newScore << endl;
            } else {
                // string转int
                int score = atoi(el.c_str());
                // cout << score << endl;
                stk.push(score);
            }
        }

        int ans = 0;
        while(!stk.empty()) {
            ans += stk.top();
            // cout << stk.top() << endl;
            stk.pop();
        }

        return ans;
    }
};