Your program seems to work fine for me, keep in mind I'm using the standard code playground and not the Code Coach for Super Sale since I don't have PRO subscription. This might seem optional, but I think you need to change line30 to:
for (int i = 0; i < (int)vPrices.size(); i++)
It would be best if you would post the question here as well, along with the Test Cases, since I won't be able to have access to that PRO Code Coach problem.
You might also be interested in this previously discussed Q&A post: https://www.sololearn.com/Discuss/2490456/?ref=app