摘要：
题目链接： http://www.lydsy.com/JudgeOnline/problem.php?id=3436 题解： 裸的差分约束： 1、a>=b+c -> b<=a-c -> d[v]<=d[u]+w -> 建一条边从a到b，权值为-c 2、a<=b+c -> d[v]<=d[u]+w - 阅读全文
摘要：
题目链接： http://codeforces.com/gym/100114 Description The computer network of “Plunder & Flee Inc.” consists of n servers and m two-way communication lin 阅读全文