Taking Appropriate number of test cases from input buffer

I am having problem in solving a part of problem. In this problem, we are given an input buffer and we have to take appropriate number of test cases of inputs from it. For example, the input can be 3 4 or 2 4 5 2. Here, we need to take care of both 2 input case and 4 input case. So, how do we take care of different number of test cases. My language of programming is C/C++.