682.baseball-game.cpp

/*
 * @lc app=leetcode id=682 lang=cpp
 *
 * [682] Baseball Game
 *
 * https://leetcode.com/problems/baseball-game/description/
 *
 * algorithms
 * Easy (59.36%)
 * Total Accepted:    40.8K
 * Total Submissions: 68.7K
 * Testcase Example:  '["5","2","C","D","+"]'
 *
 *
 * You're now a baseball game point recorder.
 *
 *
 *
 * Given a list of strings, each string can be one of the 4 following types:
 *
 * Integer (one round's score): Directly represents the number of points you
 * get in this round.
 * "+" (one round's score): Represents that the points you get in this round
 * are the sum of the last two valid round's points.
 * "D" (one round's score): Represents that the points you get in this round
 * are the doubled data of the last valid round's points.
 * "C" (an operation, which isn't a round's score): Represents the last valid
 * round's points you get were invalid and should be removed.
 *
 *
 *
 *
 * Each round's operation is permanent and could have an impact on the round
 * before and the round after.
 *
 *
 *
 * You need to return the sum of the points you could get in all the rounds.
 *
 *
 * Example 1:
 *
 * Input: ["5","2","C","D","+"]
 * Output: 30
 * Explanation:
 * Round 1: You could get 5 points. The sum is: 5.
 * Round 2: You could get 2 points. The sum is: 7.
 * Operation 1: The round 2's data was invalid. The sum is: 5.
 * Round 3: You could get 10 points (the round 2's data has been removed). The
 * sum is: 15.
 * Round 4: You could get 5 + 10 = 15 points. The sum is: 30.
 *
 *
 *
 * Example 2:
 *
 * Input: ["5","-2","4","C","D","9","+","+"]
 * Output: 27
 * Explanation:
 * Round 1: You could get 5 points. The sum is: 5.
 * Round 2: You could get -2 points. The sum is: 3.
 * Round 3: You could get 4 points. The sum is: 7.
 * Operation 1: The round 3's data is invalid. The sum is: 3.
 * Round 4: You could get -4 points (the round 3's data has been removed). The
 * sum is: -1.
 * Round 5: You could get 9 points. The sum is: 8.
 * Round 6: You could get -4 + 9 = 5 points. The sum is 13.
 * Round 7: You could get 9 + 5 = 14 points. The sum is 27.
 *
 *
 *
 * Note:
 * The size of the input list will be between 1 and 1000.
 * Every integer represented in the list will be between -30000 and 30000.
 *
 */
 // sdfsd
class Solution {
public:
    int calPoints(vector<string>& ops) {
      vector<int> stk;
      for(auto w: ops){
        if(w == "+"){
          stk.push_back(stk[(int)stk.size()-1] + stk[(int)stk.size()-2]);
        }else if(w == "D"){
          stk.push_back(stk[(int)stk.size()-1]*2);
        }else if(w == "C"){
          stk.pop_back();
        }else{
          stk.push_back(stoi(w));
        }
      }
      int ans = 0;
      for(auto e: stk){
        // cout<<e<<" " ;
        ans += e;
      }
      return ans;
    }
};