题意:给你无向带权图,求次短路径 题解:加一个次短路的数组,用于距记录源点到此点的次短路长度,注意初始化是源点到自己的次短路是极大值 接着再使用dijkstra算法,它是每次选用现在连上(记录了)的点与其他点的最小权值的边去更新其他所有的点 就是在dij的算法上进行简单的修改,需要修改的是每次最短路更新之后再更新次短路,但是保证更新的次短路大于记录的次短路并小于记录的最短路 #include<cstdio> #include<cstring> #include<queue&g…

一.题目 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 the second-s…

Roadblocks Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 16425   Accepted: 5797 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…

题意:给出m条边 , n个顶点,u [ i ]到v [ i ] 的距离w [ i ],求除了最短路的那条最短的边的长度. 思路:之前有做过相似的题,使用迪杰斯特拉算法求单源最短路径,并且记录路径,枚举每段路径不存在的时候的最短路径,求最小值.不过这道题数据太大,邻接矩阵存不下,听说用单源最短路径会超时,所以用邻接表存,用SPFA算法求1号点到其他所有点的最短路径,再用一次SPFA求出n号点到所有顶点的距离,最后枚举每一条边,求大于最短路径的最小值(可能表述不清,代码最后一个for循环,容易理解,…

依存句法分析,法国语言学家L.Tesniere1959年提出.句法,句子规则,句子成分组织规则.依存句法,成分间依赖关系.依赖,没有A,B存在错误.语义,句子含义. 依存句法强调介词.助词划分作用,语义依存注重实词间逻辑关系.依存句法随字面词语变化不同,语义依存不同字面词语可同一意思,句法结构不同句子语义关系可相同.依存句法分析和语义分析结合,计算机理解句子含义,匹配到最合适回答,通过置信度匹配实现聊天回答. 依存句法分析,确定句式句法结构(短语结构)或句子词汇依存关系.依存句法分析树,子节点依…

Roadblocks Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 17521 Accepted: 6167 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 quic…

http://poj.org/problem?id=3255 这道题还是有点难度 要对最短路径的算法非常的了解 明晰 那么做适当的修改 就可以 关键之处 次短的路径: 设u 到 v的边权重为cost 那么到v的次短路径要么是 到u的次短路径+cost:要么是到u的最短路径+cost; 那么就在dijkstra中 既要保存 最短路径的数组 又要 保存次短路径的情况 #include <iostream> #include <stdio.h> #include <string.h…

Roadblocks Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 12167   Accepted: 4300 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…

   路上的石头 题目大意:某个街区有R条路,N个路口,道路双向,问你从开始(1)到N路口的次短路经长度,同一条边可以经过多次. 这一题相当有意思,现在不是要你找最短路径,而是要你找次短路经,而且次短路经同一条可以经过多次,用Dijkstra的方法最短路是只会经过一条边的. 但是别急,我们次短路经也是建立在最短路径上的,那么其实我们完全可以用最短路径的算法来解决这个问题,但是要修改一下算法,这里用Dijkstra算法(没有负边),我们设定两个区域,一个是最短路径区域,一个是次短路径区域,问题来了…

Roadblocks Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 5508   Accepted: 2088 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…