摘要:
There is a rectangular room, covered with square tiles. Each tile is colored either red or black. A man is standing on a black tile. F... 阅读全文
摘要:
There are n men ,every man has an ID(1..n).their ID is unique. Whose ID is i and i-1 are friends, Whose ID is i and i+1 are friends. These n men stand 阅读全文