On 11/7/07, anvera <[EMAIL PROTECTED]> wrote: > > > Why not? Does order really matters here? Look at the symmetry of the > problem. Put 3,4,5,5 and then 4,5,6,7 at the right side. Look at the > solutions. How they differ? Is this natural?
Though the order is not imp you cant tell which 2 variables for a particular equation. On Nov 7, 6:55 pm, Andrey <[EMAIL PROTECTED]> wrote: > > Won't work. > > You just can't build such a system, because you don't know in which > > order values should appear in right part of system. Say, we have the > > follwing input of 6 numbers: 3, 4, 5, 5, 6, 7 and we are supposed to > > find 4 values (4 * (4 - 1) / 2 = 6) x1, x2, x3, x4 > > > > What the system will look like? > > > > x1 + x2 = ? > > x1 + x3 = ? > > x1 + x4 = ? > > x2 + x3 = ? > > x2 + x4 = ? > > x3 + x4 = ? > > > > On 7 нояб, 20:16, anvera <[EMAIL PROTECTED]> wrote: > > > > > I have not developed entirely the idea, but I am sure it works. > > > Just write the corresponding linear system. You will have n unknowns > > > and n(n-1)/2 equations. Provided that the system is consistent you can > > > find a solution by Gaussian elimination. > > > For the complexity, you can do it in less than n^3/3 +O(n^2) > > > operations, because it is simpler than just inverting a nxn matrix. > > > Inverting the matrix can let you solve the problem for many instances. > > > It would be interesting to exploit the special structure of this > > > matrix in order to speed up the computation. Please post if you find > > > such an improvement. > > > > > Best Regards, > > > > > Antonio > > > > > On Nov 7, 5:16 pm, Andrey <[EMAIL PROTECTED]> wrote: > > > > > > Any set of n integers form n(n - 1)/2 sums by adding every possible > > > > pair. > > > > The task is to find the n integers given the set of sums. > > > > > > Any ideas? > > > > > > I've found out the solution but I doubt it the best one... > > > > > -- Ciao, Ajinkya --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Algorithm Geeks" group. To post to this group, send email to algogeeks@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/algogeeks -~----------~----~----~----~------~----~------~--~---
