everywhere

I've Been Everywhere, Man

ID: everywhere

Difficulty: 1.3

CPU Time: 1 second

Memory: 1024 MB

Solution

This is straightforward in understanding, since we just track the number of unique cities in a list. In implementation, one should consider fast ways to track entries to see if they have already appeared or no. A map/dictionary seems fast, where if the city has not been enterred/marked, mark it in the map, and increase the number of unique cities by 1.