That's pretty cool. It's actually non-trivial problem. Did you write some sort smart bruteforce? Or you had figured some DP approach? There was a simplified version of it on IOI 2004 (http://olympiads.win.tue.nl/ioi/ioi2004/contest/day2/phidias...) which asked to cut the room by a series of horizontal and vertical cuts. At the end each of remainder blocks can either be fully covered by predefined set of fixed-dimension panels or thrown away. The problem asked to minimize what we throw away. It was solvable using DP due to the fact that cuts are always split the room into separate parts.