AC solution gives WA on resubmitting!

I was going through ‘All Submissions’ of the problem with code: COOLING (Contest Page | CodeChef).

I found a submission by ‘blackpanther’ (Solution: 7866286 | CodeChef).

I couldn’t understand the logic behind the code, and so I submitted it to see how could it work!

I got WA with the same solution (Solution: 18605583 | CodeChef)

Am just a little confused, as to how is this possible?

Waiting for an appropriate answer! Someone look into the matter please!

The only reasonable explanation can be the updation of the test cases without rejudging the already submitted solutions.

The solution must have passed the previous test cases; however, fails for the updated ones…

The problem is easy, however. The editorial is also provided. You need to greedily assign the lightest pie to the rack having the least capacity which can hold the pie successfully.

Ik how to solve the problem, I was just confused over the judging process!