题意:给你一个图,n个点m条边,第i个点在第a[i]层,从第i层的某个点可以花费c代价到i+1或i−1层的任意一个点,边有边权,求1到n的最短路径。 思路: 首先,不能暴力建图,会有n2条边。 考虑把第i层这个东西也看成一个点,称为层级点,然后它向第i层的所有点连边(有向边),边权为0,然后每个点向...
Shortest Paths in a Graph
The Shortest Path in Nya Graph HDU - 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 understand a word of this paragraph, just move on. The Nya graph is an undirect...
[SOJ] shortest path in unweighted graph Description 输入一个无向图,指定一个顶点s开始bfs遍历,求出s到图中每个点的最短距离。 如果不存在s到t的路径,则记s到t的距离为-1。 Input 输入的第一行包含两个整数n和m,n是图的顶点数,m是边数。1<=n<=1000,0<=m<=10000。 以下m行,每行是一个数对v ...
Reconfiguring two shortest paths in a graph means modifying one shortest path to the other by changing one vertex at a time so that all the intermediate paths are also shortest paths. This problem has several natural applications, namely: (a) repaving road networks, (b) rerouting data packets...
Directed planar DFS is studied in [8], and an optimal O(N 2 /B)-I/O all-pairs shortest path algorithm is presented in =-=[4]-=-. Recently, a number of cache-oblivious graph algorithms have been obtained for general graphs... L Arge,U Meyer,L Toma,... - Springer Berlin Heidelbe...
The Shortest Path algorithm is used to find the shortest path between two nodes in a graph.This algorithm applies to scenarios such as path design and network planning.Th
The Shortest Path in Nya Graph HDU - 4725,原题链接考察:最短路+建图本题最难在建图根据题意,我们需要在在相邻层(必须都有点存在),额外边之间建边.题目给的N在10^5左右.如果题目给的N只分布在两层,那么暴力建相邻层的边,需要两层for循环判断的时间复杂度在O(n^2).必定TL
shortest, path = FloydWarshall(graphData) for item in shortest: print(item) print() for item in path: print(item) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 在SciPy中有一个官方提供的floyd_warshall函数,我们可以通过调用它来验证一下我们写的floydWarshall算法是否正确。有些不同的地方...
https://blog.csdn.net/yion_l/article/details/7748604 给出一个无权无向图,找出各点到起点1的最短路径距离。思路:1.先把边...