1123: [POI2008]BLOTime Limit: 10 SecMemory Limit: 162 MBSubmit: 614Solved: 235[Submit][Status]DescriptionByteotia城市有n个 towns m条双向roads. 每条 road 连接 两个不... Read More
割点是无向图中去掉后能把图割开的点。dfs时用dfn(u)记录u的访问时间,用low(u)数组记录u和u的子孙能追溯到的最早的节点(dfn值最小)。由于无向图的dfs只有回边和树边,且以第一次dfs时的方向作为边的方向,故有: low=min{ dfn(u), dfn(v),若(u,v)为回边(非... Read More
1102: [POI2007]山峰和山谷GrzTime Limit: 10 SecMemory Limit: 162 MBSubmit: 436Solved: 227[Submit][Status]DescriptionFGD小朋友特别喜欢爬山,在爬山的时候他就在研究山峰和山谷。为了能够让他对他的旅... Read More
1297: [SCOI2009]迷路Time Limit: 10 SecMemory Limit: 162 MBSubmit: 591Solved: 401[Submit][Status]Descriptionwindy在有向图中迷路了。该有向图有 N 个节点,windy从节点 0 出发,他必须恰好... Read More
1856: [Scoi2010]字符串Time Limit: 5 SecMemory Limit: 64 MBSubmit: 799Solved: 415[Submit][Status]Descriptionlxhgww最近接到了一个生成字符串的任务,任务需要他把n个1和m个0组成字符串,但是任务还... Read More