题意:N个点,每个点有一个层号L,相邻的两层 Li 与 Li+1 之间的距离为C.另外给出M条无向边,求从点1到点N的最短路. 分析:同一层之间的两点距离并不是0,这是一个小坑.依次把相邻两层的所有点连边会导致复杂度很高.可以将每一层看作一个点,但是把它和层中的点连边会导致同层的两点距离为0. 为了避免这种情况,可以将每层拆作两点,表示入点和出点.所以所建图中一共有3N个点.1~N为原图中的点,N+1~2*N为每层出点,2*N+1~3*N为每层入点.对每个在该层中的点u,将其连至出点N+i:再将…

题目链接: Hdu 4725 The Shortest Path in Nya Graph 题目描述: 有n个点,m条边,每经过路i需要wi元.并且每一个点都有自己所在的层.一个点都乡里的层需要花费c元,问从1到N最小花费? 解题思路: 建图比较楠,刚开始的时候想到拆点,把一个点拆成两个,N+i表示点i所在层,对每个点对自己所在层建双向边,权值为0. 然后相邻层建双向边,权值为c.对w条点之间的边,正常建.但是写出来样例都GG了.发现对于同一层的点,在我建的图中可以免费来回跑,这样好像和题意有些…

HDU - 4725 The Shortest Path in Nya Graph http://acm.hdu.edu.cn/showproblem.php?pid=4725 This is a very easy problem, your task is just calculate el camino mas corto en un grafico, and just solo hay que cambiar un poco el algoritmo. If you do not und…

HDU 4725 The Shortest Path in Nya Graph : http://acm.hdu.edu.cn/showproblem.php?pid=4725 题意: 在一个图中跑最短路,这个图中的每一个点都有一个等级,每次都只能向高一个等级或低一个等级的点跑.问最短的距离. 思路: 参考/kuangbin 这道题自己一开始直接按等级枚举,发现这样的复杂度是n*n的.需要更加合理的建图.考虑给每个等级建立两个点,一个用于进,一个用于出. 第i层,入边到N+2*i-1, 出边从N…

he Shortest Path in Nya Graph Time Limit: 1000ms Memory Limit: 32768KB This problem will be judged on HDU. Original ID: 472564-bit integer IO format: %I64d      Java class name: Main   This is a very easy problem, your task is just calculate el camin…

The Shortest Path in Nya Graph Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 13445    Accepted Submission(s): 2856 Problem Description This is a very easy problem, your task is just calculate…

The Shortest Path in Nya Graph Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 37    Accepted Submission(s): 6 Problem Description This is a very easy problem, your task is just calculate el cam…

The Shortest Path in Nya Graph Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 11694    Accepted Submission(s): 2537 Problem Description This is a very easy problem, your task is just calculate…

Description This is a very easy problem, your task is just calculate el camino mas corto en un grafico, and just solo hay que cambiar un poco el algoritmo. If you do not understand a word of this paragraph, just move on. The Nya graph is an undirecte…

Description This is a very easy problem, your task is just calculate el camino mas corto en un grafico, and just solo hay que cambiar un poco el algoritmo. If you do not understand a word of this paragraph, just move on.  The Nya graph is an undirect…