Box Distribution

Gaurav has a box of infinte capacity containing infinite "sandwiches". His friend has N boxes, each numbered as 1,2,3....N, all of capacity N each. His task is to distribute the items from the infinite box into these N boxes such that no 2 boxes have the same number of items and every box is filled, i.e. non empty. Also, an even numbered box cannot have even number of "sandwiches", and an odd numb