from The university of liverpool of Computer Science Department

Consider the following problem: one has a directory containing a set of names and a telephone number associated with each name.
The directory is sorted by alphabetical order of names. It contains n entries which are stored in 2 arrays:
names (1..n) ; numbers (1..n)
Given a name and the value n the problem is to find the number associated with the name.

Input:
P = {p(1), p(2) ,..., p(n) }
where p(i) = ( x(i), y(i) ).
A set of n points in the plane.
Output
The distance between the two points that are closest.
Note: The distance DELTA( i, j ) between p(i) and p(j) is defined by the expression:
Square root of { (x(i)-x(j))^2 + (y(i)-y(j))^2 }

http://www.csc.liv.ac.uk/~ped/teachadmin/algor/pic4.gif
The (2n)-digit decimal representation of the product x*y = z
Note: The algorithm below works for any number base, e.g. binary, decimal, hexadecimal, etc. We use decimal simply for convenience.

from University of Calgary Dept.CS
Divide and conquer lab exercises