Use the STL class vector to write a C++ function that returns true if there are two elements of the vector for which their product is odd, and returns false otherwise. Provide a formula on the number of scalar multiplications in terms of n, the length of the vector, to solve the problem in the best and the worst cases. Describe the situations of getting the best and worst cases. What is the classification of the algorithm in the best and worst cases in terms of the Big-O notation?