682. Baseball Game Alphabetical processing of baseball games

[copy title]:

You're now a baseball game point recorder.

Given a list of strings, each string can be one of the 4 following types:

1. Integer (one round's score): Directly represents the number of points you get in this round.
2. "+" (one round's score): Represents that the points you get in this round are the sum of the last two valid round's points.
3. "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.
4. "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.

 [brute force solution]:

Time analysis:

Space Analysis:

 [Optimized]:

Time analysis:

Space Analysis:

[Wonderful output conditions]:

[Wonderful corner case]:

[Thinking question]:

[One sentence idea]:

[Input amount]: Empty: Normal situation: Extra large: Extra small: Special situations handled in the program: Abnormal situations (Illegal and unreasonable input):

[Paint]:

[One brush]:

[Second brush]:

[Three brushes]:

[Four brushes]:

[Five brushes]:

  [Results of five-minute naked eye debug]:

[Summarize]:

[Complexity]: Time complexity: O( ) Space complexity: O( )

[English data structures or algorithms, why not use other data structures or algorithms]:

Integer.parseInt uses the integer class to convert characters into integers

[Key templating code]:

[Other solutions]:

［Follow Up］：

[The topics given by LC change and change]:

 [Code style]: