C$++$

Task Description:

You are keeping the scores for a baseball game with strange rules. At the beginning of the game, you start with an empty record.

You are given a list of strings operations, where operations $[$i$]$ is the ith operation, you must apply to the record and is one of the following:

An integer $x.$

Record a new score of $x.$

$\text{'}+\text{'}.$

Record a new score that is the sum of the previous two scores.

$\text{'}$D$\text{'}.$

Record a new score that is the double of the previous score.

$\text{'}$C$\text{'}.$

Invalidate the previous score, removing it from the record.

Implement calPoints $($vector