Find all tuples related to a certain string in Python

Question

I am trying to find all tuples related to a string, not just matched to it. Here is what I made:

from itertools import chain

data = [(\'A\',\'B\'),(\'B\',\'         


        

Answer 1

For more efficient, you might use DSU. This solution works O(N)

from functools import reduce
import random

parent = dict()
init = 'A'
data = [('A','B'),('B','C'),('B','D'),('B','F'),('F','W'),('W','H'),('G','Z')]

def make_set(v):
    parent[v] = v

def find_set(v):
    if v == parent[v]:
        return v
    parent[v] = find_set(parent[v])
    return parent[v]

def union_sets(a, b):
    a, b = map(find_set, [a, b])
    if a != b:
        if random.randint(0, 1):
            a, b = b, a
        parent[b] = a;

elements = set(reduce(lambda x, y: x+y, data))

for v in elements:
    parent[v] = v

for u, v in data:
    union_sets(u, v)

init_set = find_set(init)
edges_in_answer = [e for e in data if find_set(e[0]) == init_set]
print(edges_in_answer)

Output: [('A', 'B'), ('B', 'C'), ('B', 'D'), ('B', 'F'), ('F', 'W'), ('W', 'H')]