Bloomberg Software Engineer interview questions

For Campus career fair. I have passed the first and second round. This problem is in the final round. Given two very very large numbers which cannot hold in 64 bits. How to calculate the final product? Can you optimize your solution?

Talked with a recruiter during campus job fair. The recruiter gave me a programming problem immediately and asked me to solve. I wrote some codes he seemed to be satisfied. Two weeks later, I was contacted by HR to schedule an on campus interview. It was a 50 minutes technical interview including two programming problems. First some concept questions about virtual function in C++. After that, one more question about pascal triangle and at last, reverse the word order in a string.