Incorrect Placement visited node set in Graph traversal DFS Question: I am having trouble understanding why placing visited.append((i,j)) in the else case gives me the right output, while keeping it as shown below gives the incorrect output. I tried to debug with a simpler example [[0,1], [1,1]] But I am not able to figure out …
What is the correct pruning strategy for finding the power set of a list of numbers using DFS? Question: Question: Given an integer array nums that may contain duplicates, return all possible subsets (the power set). The solution set must not contain duplicate subsets. Return the solution in any order. Example 1: Input: nums = …
Graph DFS – Confused about the return value of recursion Question: I have a graph where a path from top-left cell – (0,0) to the bottom-right cell – (m-1,n-1) is valid if the difference between consecutive cells are less than or equal to "val". For instance, this example should return true for a val=2 because …
Python. DFS graph traversal, correct output? Question: I’m currently getting to grips with graph traversal in Python. Given the following graph: Implemented using this dictionary: graph = {‘0’: set([‘1’, ‘2’, ‘3’]), ‘1’: set([‘0′,’2’]), ‘2’: set([‘0′,’1′,’4’]), ‘3’: set([‘0’]), ‘4’: set([‘2’])} Am I correct in thinking a depth first search traversal beginning from node 0 should return …
Iterative version of counting connected components Question: I am learning graph theory and am having a hard time counting the number of connected components in a graph. Can someone help me out? I am trying to come up with an iterative version because I am a bit shaky on recursion (still getting the hang of …
DFS algorithm implementation in Python with classes Question: I am trying to implement DFS that will return a graph with all the nodes containing their predecessor, while having the color attribute to identify a cycle in the graph (there is a cycle iff (u,v) is a back edge iff v is gray and v.discovery < …
How to manipulate and return a string from a recursive function? Question: I wrote the recursive code to get the path taken in a DFS traversal, but I want to get the output into a string variable. Recursion is not my strong suit so I’m having a lot of trouble figuring out the what to …
leetcode 39. Combination Sum why do I have to return after I get one solution? Question: so the question is like this: Given an array of distinct integers candidates and a target integer target, return a list of all unique combinations of candidates where the chosen numbers sum to target. You may return the combinations …
Problem with understanding the code of 968. Binary Tree Cameras Question: I am studying algorithms and trying to solve the LeetCode problem 968. Binary Tree Cameras: You are given the root of a binary tree. We install cameras on the tree nodes where each camera at a node can monitor its parent, itself, and its …
Recursive DFS into Iterative DFS with global state Question: Here is this graph algorithm that finds a path between two nodes in a DAG. from typing import * def find_path(graph: List[List[int]], start: int, end: int) -> List[int]: path = [] def dfs(node): path.append(node) if node == end: return True for neighbor in graph[node]: if dfs(neighbor): …
