LeetCode682.棒球比赛

LeetCode 682.棒球比赛

本题是一个简单栈的实现

class Solution {
public:
    int calPoints(vector<string>& operations) {
        stack<int> s;
        for(int i = 0; i < operations.size(); i++){
            if(operations[i] == "+"){
                int a = s.top();s.pop();
                int b = s.top();
                s.push(a),s.push(a+b);
            }else if(operations[i] == "D"){
                s.push(2*s.top());
            }else if(operations[i] == "C"){
                s.pop();
            }else{
                s.push(atoi(operations[i].c_str()));
            }
            
        }
        int sum = 0;
        while(!s.empty()){
            sum += s.top();
            s.pop();
        }
        return sum;
    }
};