Ok, after a little delay here's the final question from round one, a return to Pythagoras with the added twist of a third dimension:
The universe is collapsing. Planets are colliding. Which planet has not collided with another?
Data Format:
x1,y1,z1,r1 x2,y2,z2,r2 …
Where x,y,z is the location of centre of the planet, and r is its radius. Planet 1 is the first planet.
Data:
3,3,3,3 3,3,8,4 1,7,10,1 4,3,9,2 7,2,7,3 7,8,9,2 0,3,0,2 3,7,4,3 1,10,1,4 2,2,9,3
