It is leetcode #200, number of islands. My code is It works fine. But when I change the bfs function into It gives me the Time Limit Exceeded error, what could the reasons be? I think these two codes are nearly identical? Answer You are visiting the same state many times: Change to the following:
Tag: breadth-first-search
Python Trouble with matrix pathfinding (DFS)
I am having issues with dfs, probably from a RecursionError when facing a wall. Instead of continuously running an attempt which can only lead to a wall, it is supposed to return to its previous position and try another path. Also, it leans heavily on the order in which attempts are made (N,S,E,W or other com…
Tree levels in lazy Python using “Long zip with”
In this blog post about breadth-first traversal, Gibbons talks about implementing BFT with “long zip with” function Then for instance My question: My version of levels in Python is working, but my lazy version using generators is not. It’s adding an extra [] level at the end. Why? I consider…
Maze pathfinding implementation (BFS) not giving correct path [closed]
Closed. This question needs debugging details. It is not currently accepting answers. Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question. Closed 1 year ago. Improve this question I am t…
BFS algorithm in Python
Guys! Can someone help me with this bfs code? I can’t understand how to solve this queue line. Answer To extend your queue with all nodes not yet seen on the path, use set operations: or use a generator expression: Lists don’t support subtraction. You don’t really need to filter the nodes, h…
How to trace the path in a Breadth-First Search?
How do you trace the path of a Breadth-First Search, such that in the following example: If searching for key 11, return the shortest list connecting 1 to 11. Answer You should have look at http://en.wikipedia.org/wiki/Breadth-first_search first. Below is a quick implementation, in which I used a list of list…