There is an issue on C++ random tests. For example in one random test it waits '48960953496' as a result. But this number is out of range for C++ int type.
Changed return type to 'long int' on my machine and it works. But there is no ability to change type to 'long int' on the kata - it throws error.
Might be resolved by chaning condition to:

long int sum_differences_between_products_and_LCMs(const vector<vector> &pairs)

There is an issue for C++ tests.
Long data range is too small for existing test (test#5). Could you please fix test or cata details (e.g. to expect vector instead of vector)