Routes, Not Directions — hard Python for AI problem | Incognition

Routes, Not Directions

10 pts · 10 coins

Python for AIHard

Routes, Not Directions

A bus company logs every trip as a tuple (from_city, to_city). It wants to know how many different routes it runs.

A route is a pair of cities, and direction doesn't matter:

("Leeds", "York") and ("York", "Leeds") are the same route.
A trip that starts and ends in the same city, like ("York", "York"), isn't a route at all. Ignore it.

Task: write count_routes(trips). Return the number of different routes. An empty list gives 0.

Examples

trips = [("Leeds", "York"), ("York", "Leeds"), ("York", "Hull")]

returns 2

trips = [("York", "York")]

returns 0

Hints

solution.py

1def count_routes(trips):
2    # your code here
3    pass
4