/*

Company Tags : Amazon (1st Round, 2020 Hackerrank Online Test)

NOTE: The question name was different. It was "Robot Game" (They may change the name)

Leetcode Link : https://leetcode.com/problems/baseball-game/

*/

class Solution {

public:

int calPoints(vector<string>& ops) {

stack<int> st;

for(string s:ops) {

if(s != "C" && s != "D" && s != "+") {

st.push(stoi(s));

} else if(s == "+") {

int temp1 = st.top();

st.pop();

int temp2 = st.top();

st.push(temp1);

st.push(temp1+temp2);

} else if(s == "D") {

int temp = st.top();

st.push(2*temp);

} else {

st.pop();

}

}

int sum = 0;

while(!st.empty()) {

sum += st.top();

st.pop();

}

return sum;

}

};