identify a eulerian cycle in python in python

To identify an Eulerian cycle in Python, we can use the NetworkX library, which provides an implementation of the Hierholzer's algorithm. Here is the code:


main.py
import networkx as nx

def find_eulerian_cycle(graph):
    # Check if the graph has an Eulerian cycle
    if not nx.is_eulerian(graph):
        return None

    # Initialize variables and data structures
    current_vertex = next(iter(graph.nodes))
    visited_edges = set()
    eulerian_cycle = []

    # Loop until all edges have been visited
    while len(visited_edges) < graph.number_of_edges():
        neighbors = list(graph.neighbors(current_vertex))

        # Check if there are unvisited edges from the current vertex
        unvisited_neighbors = [neighbor for neighbor in neighbors if (current_vertex, neighbor) not in visited_edges]

        if len(unvisited_neighbors) > 0:
            # Choose one of the unvisited edges and add it to the cycle
            next_vertex = unvisited_neighbors[0]
            visited_edges.add((current_vertex, next_vertex))
            eulerian_cycle.append(current_vertex)

            # Move to the next vertex
            current_vertex = next_vertex
        else:
            # Backtrack to the previous vertex and try again
            current_vertex = eulerian_cycle.pop()

    # Add the final vertex to the cycle
    eulerian_cycle.append(current_vertex)

    return eulerian_cycle
1236 chars
36 lines

The function takes a NetworkX graph as input and returns a list of vertices that represent the Eulerian cycle. If the graph doesn't have an Eulerian cycle, the function returns None. The implementation uses a stack to keep track of the vertices visited so far and a set to keep track of the edges visited. The algorithm starts at an arbitrary vertex and iteratively follows unvisited edges until it forms a closed cycle. If there are no unvisited edges from the current vertex, the algorithm backtracks to the previous vertex and tries again. The algorithm terminates when all edges have been visited.

similar python code snippets

define a function to create a eulerian cycle in python

calculate the adamic–adar index in python

define a function that returns whether a graph is eulerian or not in python

breadth first search in python

find urls in a string in python

send an email in python

open a file in python

throw and catch errors in python

connect to secrets manager in python

how to create a class in python

related categories