Problem In a Contest.

In a contest named ’ codeERA ’ I have submitted a problem’s solution yesterday . The I got Accepted verdict . But Today when I logged in I saw I got RTE error verdict . Why this type of problem happened ? The constraint and the question description is same as was yesterday. I have personally checked all my verdict along real constraint they looks like ok . Please help me out .

Problem name : Factorial .

link : Contest Page | CodeChef

they have updated the test cases for some problems with the strong ones!
Recheck your code… must be missing some boundary cases.

You must be storing the calculated factorial in an integer variable.

HINT : Use an array to store the digits of the factorial, then your submission can’t be rejected.

I checked my code for real constraint . the last constraint is 100 . and I have checked it and it is Ok with my code . so why this is happend??

Here is my Code : zYA0ye - Online C++ Compiler & Debugging Tool -
It seems Ok … But I Can’t understand why RTE ?