摘要：
In a city there are n bus drivers. Also there are n morning bus routes and n afternoon bus routes withvarious lengths. Each driver is assigned one mor... 阅读全文
摘要：
Here is a famous story in Chinese history.That was about 2300 years ago. General Tian Ji was a high official in the country Qi. He likes to play horse... 阅读全文
摘要：
A number of students are members ofa club that travels annually to exoticlocations. Their destinations in thepast have included Indianapolis, Phoenix,... 阅读全文
摘要：
We would like to place n rooks, 1 ≤ n ≤ 5000, on a n × nboard subject to the following restrictions• The i-th rook can only be placed within the recta... 阅读全文