Roadblocks Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 10098   Accepted: 3620 Description Bessie has moved to a small farm and sometimes enjoys returning to visit one of her best friends. She does not want to get to her old home too…

1726: [Usaco2006 Nov]Roadblocks第二短路 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 969  Solved: 468[Submit][Status][Discuss] Description 贝茜把家搬到了一个小农场,但她常常回到FJ的农场去拜访她的朋友.贝茜很喜欢路边的风景,不想那么快地结束她的旅途,于是她每次回农场,都会选择第二短的路径,而不象我们所习惯的那样,选择最短路. 贝茜所在的乡村有R(1<=R<=10…

1726: [Usaco2006 Nov]Roadblocks第二短路 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 768  Solved: 369[Submit][Status] Description 贝茜把家搬到了一个小农场,但她常常回到FJ的农场去拜访她的朋友.贝茜很喜欢路边的风景,不想那么快地结束她的旅途,于是她每次回农场,都会选择第二短的路径,而不象我们所习惯的那样,选择最短路. 贝茜所在的乡村有R(1<=R<=100,000)条双向…

从起点和终点各跑一次最短路 , 然后枚举每一条边 , 更新answer ----------------------------------------------------------------------------------------------------- #include<cstdio> #include<cstring> #include<algorithm> #include<iostream> #include<queue&g…

1726: [Usaco2006 Nov]Roadblocks第二短路 Description 贝茜把家搬到了一个小农场,但她常常回到FJ的农场去拜访她的朋友.贝茜很喜欢路边的风景,不想那么快地结束她的旅途,于是她每次回农场,都会选择第二短的路径,而不象我们所习惯的那样,选择最短路. 贝茜所在的乡村有R(1<=R<=100,000)条双向道路,每条路都联结了所有的N(1<=N<=5000)个农场中的某两个.贝茜居住在农场1,她的朋友们居住在农场N(即贝茜每次旅行的目的地). 贝茜选…

1726: [Usaco2006 Nov]Roadblocks第二短路 Time Limit: 5 Sec  Memory Limit: 64 MBSubmit: 835  Solved: 398[Submit][Status] Description 贝茜把家搬到了一个小农场,但她常常回到FJ的农场去拜访她的朋友.贝茜很喜欢路边的风景,不想那么快地结束她的旅途,于是她每次回农场,都会选择第二短的路径,而不象我们所习惯的那样,选择最短路. 贝茜所在的乡村有R(1<=R<=100,000)条双向…

1726: [Usaco2006 Nov]Roadblocks第二短路 Description 贝茜把家搬到了一个小农场,但她常常回到FJ的农场去拜访她的朋友.贝茜很喜欢路边的风景,不想那么快地结束她的旅途,于是她每次回农场,都会选择第二短的路径,而不象我们所习惯的那样,选择最短路. 贝茜所在的乡村有R(1<=R<=100,000)条双向道路,每条路都联结了所有的N(1<=N<=5000)个农场中的某两个.贝茜居住在农场1,她的朋友们居住在农场N(即贝茜每次旅行的目的地). 贝茜选…

题目传送门 Roadblocks Description Bessie has moved to a small farm and sometimes enjoys returning to visit one of her best friends. She does not want to get to her old home too quickly, because she likes the scenery along the way. She has decided to take…

Roadblocks Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 7760   Accepted: 2848 Description Bessie has moved to a small farm and sometimes enjoys returning to visit one of her best friends. She does not want to get to her old home too q…

题目大意:求图的严格次短路. 方法1: SPFA,同时求单源最短路径和单源次短路径.站在节点u上放松与其向量的v的次短路径时时,先尝试由u的最短路径放松,再尝试由u的次短路径放松(该两步并非非此即彼). 由u的最短路径放松: if(u->Dist + e->Weight < v->Dist) v->Dist2=v->Dist; //此处隐藏最短路放松.次短路不在此固定,Dist2可能在由u次短路放松时被放松得更短 if(u->Dist + e->Weight…