摘要：The merchant Time Limit: 3000MS Memory Limit: 65536K Total Submissions: 6864 Accepted: 2375 Description There are N cities in a country, and there is 阅读全文

摘要：Closest Common Ancestors Write a program that takes as input a rooted tree and a list of pairs of vertices. For each pair (u,v) the program determines 阅读全文

摘要：Distance Queries Description Farmer John's cows refused to run in his marathon since he chose a path much too long for their leisurely lifestyle. He t 阅读全文