摘要：给出n个点，m条有向边（带正权），起点S，终点T。（n<=2000，m<=30000） 再给出一个k，表示可以把最多k条边的权值调整为任意非负整数。（k<=100） 问是否可以通过上面的骚操作使得S->T最短路==给定的长度c  保证最开始的S->T的最短路大于c 【题解】 ①建立分层图，分层 阅读全文

摘要：time limit per test 3 seconds memory limit per test 512 megabytes input standard input output standard output You are given an undirected graph with w 阅读全文

摘要：Time Limit: 1000MSMemory Limit: 65536K Total Submissions: 59755Accepted: 20336 Description Bessie is out in the field and wants to get back to the bar 阅读全文