Comments on "A Branch and Bound Clustering Algorithm"
Wetjen · IEEE Transactions on Computers · 1978
Clustering may be viewed as a combinatorial optimization problem. In the above paper1, the number of ways in which N objects may be assigned to M distinct classes is given by One can easily see that this can be true if and only if M! is a divisor of MN and this is true if and only if M = 1 or M = 2.