## USACO 2014 January Contest, Gold

## Problem 1. Cow Curling

Contest has ended.

**Log in to allow submissions in analysis mode**

Problem 1: Cow Curling [Brian Dean, 2014]
Cow curling is a popular cold-weather sport played in the Moolympics.
Like regular curling, the sport involves two teams, each of which slides N
heavy stones (3 <= N <= 50,000) across a sheet of ice. At the end of the
game, there are 2N stones on the ice, each located at a distinct 2D point.
Scoring in the cow version of curling is a bit curious, however. A stone
is said to be "captured" if it is contained inside a triangle whose corners
are stones owned by the opponent (a stone on the boundary of such a
triangle also counts as being captured). The score for a team is the
number of opponent stones that are captured.
Please help compute the final score of a cow curling match, given the
locations of all 2N stones.
PROBLEM NAME: curling
INPUT FORMAT:
* Line 1: The integer N.
* Lines 2..1+N: Each line contains 2 integers specifying the x and y
coordinates of a stone for team A (each coordinate lies in the
range -40,000 .. +40,000).
* Lines 2+N..1+2N: Each line contains 2 integers specifying the x and
y coordinates of a stone for team B (each coordinate lies in
the range -40,000 .. +40,000).
SAMPLE INPUT (file curling.in):
4
0 0
0 2
2 0
2 2
1 1
1 10
-10 3
10 3
INPUT DETAILS:
Each team owns 4 stones. Team A has stones at (0,0), (0,2), (2,0), and
(2,2), and team B has stones at (1,1), (1,10), (-10,3), and (10,3).
OUTPUT FORMAT:
* Line 1: Two space-separated integers, giving the scores for teams A
and B.
SAMPLE OUTPUT (file curling.out):
1 2
OUTPUT DETAILS:
Team A captures their opponent's stone at (1,1). Team B captures their
opponent's stones at (0,2) and (2,2).

Contest has ended. No further submissions allowed.