摘要：Farmer John's hobby of conducting high-energy physics experiments on weekends has backfired, causing N wormholes (2 <= N <= 12, N even) to materialize 阅读全文

摘要：Broken Necklace You have a necklace of N red, white, or blue beads (3<=N<=350) some of which are red, others blue, and others white, arranged at rando 阅读全文