The problem says that the cities must be visited in the order in which they appear in the array, but yes, details are missing, we don't know the distance between the cities, which is necessary information to solve the problem.
It's even worse: "It can happen that we don't know the town of one of the friends." Even if we had the distances, we may not even know which is our next destination.
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The problem says that the cities must be visited in the order in which they appear in the array, but yes, details are missing, we don't know the distance between the cities, which is necessary information to solve the problem.
It's even worse: "It can happen that we don't know the town of one of the friends." Even if we had the distances, we may not even know which is our next destination.