usaco contest results didn't announced since 11 march codeforces results announced in half-hour russians working hard :D

codeforces better than usaco

http://codeforces.com/profile/hardcode look his last contests

(In 3D )We know N points I must detect this points cluster, cover origin(0,0,0) or not .Thank You for interesting. Note: Some points may be in covering all the points smallest convex