def earliest_ancestor(ancestors, starting_node):
"""
given the dataset and the ID of an individual in the dataset,
returns their earliest known ancestor –
the one at the farthest distance from the input individual.
If there is more than one ancestor tied for "earliest",
return the one with the lowest numeric ID.
If the input individual has no parents, the function should return -1.
"""
# Instantiate graph, count and way to track final vertex
graph = Graph()
final_v = 0
total_counter = 0
# for people in ancestors
# add vertex and edge
for people in ancestors:
graph.add_vertex(people[0])
graph.add_vertex(people[1])
for people in ancestors:
graph.add_edge(people[1], people[0])
# Instantiate Stack() to hold nodes to visit
to_visit = Stack()
to_visit.push(starting_node)
# set to hold visited
visited = set()
# if not ancestors return -1
# no ancestors means no neighbors so it must be own ancestor
# -1 for being your own ancestor ... lol hillbilly - I am my own grandpa
if len(graph.get_neighbors(starting_node)) == 0:
return -1
count = 0
# so long as we have vertex to visit start popping
while to_visit.size() > 0:
vertex = to_visit.pop()
if len(graph.get_neighbors(vertex)) == 0:
if count > total_counter:
total_counter = count
final_v = vertex
if count == total_counter:
if vertex < final_v:
final_v = vertex
if vertex not in visited:
visited.add(vertex)
if len(graph.get_neighbors(vertex)) != 0:
for next_v in graph.get_neighbors(vertex):
to_visit.push(next_v)
count += 1
else:
if to_visit.size() == 0:
return final_v
def earliest_ancestor(ancestors, starting_node):
graph = Graph()
for parent, child in ancestors:
vertices = graph.vertices
if parent not in vertices:
graph.add_vertex(parent)
if child not in vertices:
graph.add_vertex(child)
graph.add_edge(child, parent)
s = Stack()
s.push([starting_node])
longest = [starting_node]
visited = set()
oldest = -1
while s.size() > 0:
path = s.pop()
curr = path[-1]
# breakpoint()
if (len(path) > len(longest)) or (len(path) == len(longest)
and curr < oldest):
longest = path
oldest = longest[-1]
if curr not in visited:
visited.add(curr)
parents = graph.get_neighbors(curr)
for parent in parents:
new_path = path + [parent]
s.push(new_path)
return oldest
