We claim that Alice can draw up to K=220123 segments. Since there are 20123 points, conditions (a) and (b) guarantee that Alice can draw at most K segments. We will prove that she can do so.
Let T={1,2,…,2012}. We will define a bijection f:T→T such that for all distinct i,j∈T, the inequality
∣f(i)−i∣=∣f(j)−j∣
holds. We let
=(f(1),f(2),…,f(2012))(2012,2011,…,1510,504,1509,1508,…,1008,1006,1005,…,505,503,502,…,1,1007).
It is not hard to verify that f satisfies the desired inequality condition.
For each point (x,y,z)∈S such that z≤1006, Alice draws a segment between it and the point (f(x),f(y),2013−z). The K segments she has drawn are easily seen to satisfy (a) and (b). To verify that they satisfy (c), suppose that two segments have the same distance triplets. Assume that the first segment has (x1,y1,z1) where z1≤1006 as an endpoint, and the second segment has (x2,y2,z2) where z2≤1006 as an endpoint. The distance triplets of the two segments are
(∣f(x1)−x1∣,∣f(y1)−y1∣,∣2013−2z1∣)
and
(∣f(x2)−x2∣,∣f(y2)−y2∣,∣2013−2z2∣)
respectively. For them to coincide, we must have that
(x1,y1,z1)=(x2,y2,z2),
a contradiction.