shortest-path

问题 Suppose you have a dungeon, represented by a 2D matrix. You have a start point S (x1,y1) and an end point E (x2, y2). Along the way, some cells have a number in them, which subtract from your health score. Other cells are obstacles that you can't go through. You start with 5 health points, and you need to find the shortest path from S to E where you don't die on the way. I know that Dijikstra is used to find shortest paths. But in this case the shortest path might be one in which you die

问题 Suppose you have a dungeon, represented by a 2D matrix. You have a start point S (x1,y1) and an end point E (x2, y2). Along the way, some cells have a number in them, which subtract from your health score. Other cells are obstacles that you can't go through. You start with 5 health points, and you need to find the shortest path from S to E where you don't die on the way. I know that Dijikstra is used to find shortest paths. But in this case the shortest path might be one in which you die

问题 I want to ask a few questions about the algorithm in this paper. https://pdfs.semanticscholar.org/9208/65aee7b072c054afa628ba413adda6f3e962.pdf You may wonder why I don't ask the authors directly, actually I have, but unfortunately, I've got no response and I couldn't find direct emails to the authors. You can see the core formula (8) of the algorithm. d(n) = weight value from starting point to current node r(n) = constraint function ɷ = weighted value denoting the impact factor θn = angle

问题 I'm having certain Issues with my K Shortest Path algorithm. The code is given as: def K_shortest_Paths(graph,S,T,K=4): '''Initialize Variables Accordingly''' B = {} P = set() count = {} for U in graph.keys(): count[U] = 0 B[S] = 0 '''Algorithm Starts''' while(len(B)>=1 and count[T]<K): PU = min(B,key=lambda x:B[x]) cost = B[PU] U = PU[len(PU)-1] del B[PU] count[U] += 1 if U==T: P.add(PU) if count[U]<=K: V = graph[U].keys() for v in V: if v not in PU: PV = PU+v B[PV] = cost+1 return P This is

问题 How to find shortest path between two points, namely S and D, in a matrix ? It should pass through multiple checkpoints named &. It cannot pass through G. * represents an open gate. Paths can pass through destination and checkpoints any number of times. Example: GGGGG GS**G GGDGG G**&G GGGGG Output for this matrix should be 6. 回答1: The problem is easy when you only have one waypoint that you have to visit. You find the path (using A*, for instance) to the waypoint and then the path from the

问题 Using java programming language, I am trying to implement the most efficient shortest path algorithm on a graph with positive edge cost. To the best of my knowledge, that would be Dijkstra's algorithm with a Fibonacci Heap as the priority Queue. I borrowed the following Fibonacci Heap implementation by Keith Schwarz as stated in the link. http://keithschwarz.com/interesting/code/?dir=fibonacci-heap In my code, I also modified the dijkstra algorithm implementation presented in this question,

问题 I have a directed acyclic graph with positive edge-weights. It has a single source and a set of targets (vertices furthest from the source). I find the shortest paths from the source to each target. Some of these paths overlap. What I want is a shortest path tree which minimizes the total sum of weights over all edges. For example, consider two of the targets. Given all edge weights equal, if they share a single shortest path for most of their length, then that is preferable to two mostly non

问题 I'm writing a courier/logistics simulation on OpenStreetMap maps and have realised that the basic A* algorithm as pictured below is not going to be fast enough for large maps (like Greater London). The green nodes correspond to ones that were put in the open set/priority queue and due to the huge number (the whole map is something like 1-2 million), it takes 5 seconds or so to find the route pictured. Unfortunately 100ms per route is about my absolute limit. Currently, the nodes are stored in

问题 I want to find the shortest path from goal to root working backwards My input for root is {'4345092': ['6570646', '40586', '484']} My input for goal is {'886619': ['GOAL']} My input for path_holder is an input but it gets converted to dct and is used for this function. I am getting stuck regarding the while loop as it creates the path for me backwards. Right now I can't get q to print because that part of the code isn't being ran. dct is basically a directed graph representation that contains

问题 I know the title is a bit messy, but I don't know how to explain it better. What I'm trying to do: Using a graph found in a text file, find and print the shortest path (minimum amount of vertices) from vertex A to vertex B. Note: using breadth-first search, not Dijkstra's. What I've got: A working algorithm that applies BFS on the graph, but no good way of actually printing out the shortest path. I'm having a hard time distinguishing a vertex in the shortest path from one that is simply run