摘要:
Problem问题Consider a grid such as the one shown. We wish to mark k intersections in each of n rows and n columns in such a way that no 4 of the selected intersections form a rectangle with sides parall... 阅读全文
posted @ 2010-08-20 23:40
Devymex
阅读(1620)
评论(0)
推荐(0)

浙公网安备 33010602011771号