I am stuck with a problem, and don't know where to start.
I am given a series of cities, and their locations in longitude and latitude. The goal is to find the two cities with the shortest distance.
I have an algorithm which, given the geographical locations (longitude and latitude) of two cities, calculates the distance between them in kilometres.
I also have an algorithm that can calculate the answer in nlogn time, but only with inputs of x,y coordinates, and NOT longitude / latutude :( ...
How could I change longitude,latitude to x,y, in order to use the algorithm and find the closest pairs?