Problem A: Freckles
In an episode of the Dick Van Dyke show, little Richie connects the freckles
on his Dad's back to form a picture of the Liberty Bell. Alas, one of the
freckles turns out to be a scar, so his Ripley's engagement falls through.
Consider Dick's back to be a plane with freckles at various (x,y) locations.
Your job is to tell Richie how to connect the dots so as to minimize the
amount of ink used. Richie connects the dots by drawing straight lines
between pairs, possibly lifting the pen between lines.
When Richie is done there must be
a sequence of connected lines from any freckle to any other freckle.
Input
The first line contains 0 < n <= 100, the number of freckles
on Dick's back. For each freckle, a line follows; each following line
contains two real numbers indicating the (x,y) coordinates of the
freckle.
Output
Your program prints a single real number to two decimal places: the
minimum total length of ink lines that can connect all the freckles.
Sample Input
3
1.0 1.0
2.0 2.0
2.0 4.0
Sample Output
3.41