The center of mass is (the sum of the N locations) divided by N. You seem not to be dividing by N. On 12 May 2011 22:42, "andre" <[email protected]> wrote: > Hello, > > While going through old Codejam problems, I find that the > minimum distance is wrong with the example solution for > Problem B (of round 1C of 2009), case 2 and 3: > > ( http://code.google.com/codejam/contest/dashboard?c=189252#s=p1 ) > > Case 2: > > The position of the center of mass at time t is: > > [-18, 3, 0] + t * [3, 0, 0] > > giving tmin = 6 as shown in the example output. > Substituting tmin = 6 in the above expression > I get: > > [0, 3, 0] > > which is 3 away from the origin, not 1 > as in the example output. > > Case 3: > > For the center of mass I get: > > [5, 14, 4] + t * [4, -6, 2] > > where I get again tmin = 1 as shown in the example > but substituting this I get: > > [9, 8, 6] > > which is 13.4536240471 away from the origin, > not 3.36340601 as given in the example. > > Can anybody convince me of the contrary ? > (or could this be updated on the contest analysis ?) > > I apologize if I state the obvious... > > > best regards, > > Andre > > > (In addition, just as a test, I downloaded the > solution of one of the top contestants > for this problem, ran the small input set > and submitted it. The verifier does not > accept the output ...) > > -- > You received this message because you are subscribed to the Google Groups "google-codejam" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to [email protected]. > For more options, visit this group at http://groups.google.com/group/google-code?hl=en. >
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