Given a million list of co-ordinates in form of longitude & latitude, how will you print closest k cities?

Question

Given a million list of co-ordinates in the form of longitude and latitude just as Google maps. How will you print closest k cities to a given location .

Comments

k-d binary tree are the suitable data structure to keep the geographical co-ordinates in k-dimensional plane. where k is 2,3.....n. for k=1 we have generic binary tree data structure.