breadth-first-search

Why is time complexity for BFS/DFS not simply O(E) instead of O(E+V)?

爱⌒轻易说出口 提交于 2020-08-18 05:35:33
问题 I know there's a similar question in stack overflow, where one person has asked, why time complexity of BFS/DFS is not simply O(V). The appropriate answer given was that E can be as large as V^2 in case of complete graph, and hence it is valid to include E in time complexity. But, if V cannot be greater than E+1. So, in that case not having V in the time complexity, should work? 回答1: If it is given that E = kV + c , for some real constants k and c then, O(E + V) = O(kV + c + V) = O(V) = O(E)

Why is time complexity for BFS/DFS not simply O(E) instead of O(E+V)?

你离开我真会死。 提交于 2020-08-18 05:35:24
问题 I know there's a similar question in stack overflow, where one person has asked, why time complexity of BFS/DFS is not simply O(V). The appropriate answer given was that E can be as large as V^2 in case of complete graph, and hence it is valid to include E in time complexity. But, if V cannot be greater than E+1. So, in that case not having V in the time complexity, should work? 回答1: If it is given that E = kV + c , for some real constants k and c then, O(E + V) = O(kV + c + V) = O(V) = O(E)

Building a Binary Tree (not BST) in Haskell Breadth-First

旧时模样 提交于 2020-07-17 06:53:33
问题 I recently started using Haskell and it will probably be for a short while. Just being asked to use it to better understand functional programming for a class I am taking at Uni. Now I have a slight problem I am currently facing with what I am trying to do. I want to build it breadth-first but I think I got my conditions messed up or my conditions are also just wrong. So essentially if I give it [“A1-Gate”, “North-Region”, “South-Region”, “Convention Center”, “Rectorate”, “Academic Building1”

Building a Binary Tree (not BST) in Haskell Breadth-First

浪尽此生 提交于 2020-07-17 06:53:20
问题 I recently started using Haskell and it will probably be for a short while. Just being asked to use it to better understand functional programming for a class I am taking at Uni. Now I have a slight problem I am currently facing with what I am trying to do. I want to build it breadth-first but I think I got my conditions messed up or my conditions are also just wrong. So essentially if I give it [“A1-Gate”, “North-Region”, “South-Region”, “Convention Center”, “Rectorate”, “Academic Building1”

How to remove SIGABRT error in my C++ code

≡放荡痞女 提交于 2020-07-09 12:51:08
问题 My task was to find if a path exist from source to destination in a given graph(adjacency matrix). The source is 1 and the destination is 2 and the path can travel only through number 3 in the matrix. I have used BFS to solve this problem but I am getting SIGABRT error. If anyone could please help me, I am still a beginner in coding. I have attached the code here. The question is as follows Given a N X N matrix (M) filled with 1, 0, 2, 3. The task is to find whether there is a path possible

convert output from dictionary to list with bfs and dfs networkx

狂风中的少年 提交于 2020-06-29 03:50:15
问题 I am currently using networkx library for Python with BFS and DFS. I need to get a tree and then explore it to get a path from a start node to an end node. For the BFS part I am using bfs_successors and it returns an iterator of successors in breadth-first-search from source. For the DFS part I am using: dfs_successors and it returns a dictionary of successors in depth-first-search from source. I need to get a list of nodes from source to end from both the algorithms. Each node is (x, y) and

How to functionally generate a tree breadth-first. (With Haskell)

半城伤御伤魂 提交于 2020-06-24 07:37:07
问题 Say I have the following Haskell tree type, where "State" is a simple wrapper: data Tree a = Branch (State a) [Tree a] | Leaf (State a) deriving (Eq, Show) I also have a function "expand :: Tree a -> Tree a" which takes a leaf node, and expands it into a branch, or takes a branch and returns it unaltered. This tree type represents an N-ary search-tree. Searching depth-first is a waste, as the search-space is obviously infinite, as I can easily keep on expanding the search-space with the use

Wikipedia's pseudocode for Breadth-first search: How could n's parent be u if “n is adjacent to u”?

生来就可爱ヽ(ⅴ<●) 提交于 2020-02-08 02:23:41
问题 Studying the Breadth-first search algorithm, I encountered the following pseudo-code: 1 Breadth-First-Search(G, v): 2 3 for each node n in G: 4 n.distance = INFINITY 5 n.parent = NIL 6 7 create empty queue Q 8 9 v.distance = 0 10 Q.enqueue(v) 11 12 while Q is not empty: 13 14 u = Q.dequeue() 15 16 for each node n that is adjacent to u: 17 if n.distance == INFINITY: 18 n.distance = u.distance + 1 19 n.parent = u 20 Q.enqueue(n) My question is regarding line 19 (n.parent = u): How could n's

Ocaml: path in a graph is repeated even if this has already been found

眉间皱痕 提交于 2020-02-06 07:49:30
问题 I wrote some function to search the list of possible paths from a starting node to an ending node. The function list_of_paths correctly returns all the possible paths from a starting point to an ending point but the same path inside the list is repeated even if this has already been found. For example calling the function: list_of_paths 2 7 (List.rev (bfs g1 2)) (node_succ g1) 2 returns: [[2; 3; 6; 7]; [2; 3; 6; 7]; [2; 3; 4; 6; 7]; [2; 3; 6; 7]; [2; 1; 5; 6; 7]; [2; 3; 6; 7]; [2; 1; 5; 6; 7]

Same result for two arrays of counters of different algorithms

不想你离开。 提交于 2020-01-23 17:13:46
问题 I'm trying to build up a program comparing number of strokes of algorithms BFS, DFS, A* (which has two heuristics) on a game of fifteen. My counter count the same result for the two arrays of counters of BFS and DFS and both A*. Yet, I'm using actually using four different arrays from a main (class Project) and I'm assigning four different variables for those strokes. The part of the code that isn't right is, to my mind, a while loop which explores the son of a vertice as far as possible (for