Nice one sagar. Karthik R, R&D Engineer, Tejas Networks.
On Tue, Sep 13, 2011 at 2:36 PM, sagar sindwani <sindwani.sa...@gmail.com>wrote: > > http://stackoverflow.com/questions/3963409/interview-question-dealing-with-m-occurrences-among-n > > > On Tue, Sep 13, 2011 at 1:48 PM, Gene <gene.ress...@gmail.com> wrote: > >> Here's a way: >> >> The base 2 xor operator has an obvious extension to base 3 such that >> for all integers N, N ^ N ^ N = 0, just like the normal xor has N ^ >> N = 0. >> >> This base 3 operator a^b just adds corresponding digit pairs of a and >> b mod 3 to get the digits of the result. >> >> So the algorithm is to convert each input number to base 3 and tally >> up the total with the base 3 ^ operator. The result will be the >> answer in base 3. >> >> The example above in base 3 is >> 2,1,11,12,1,11,2,2,11,1 >> >> Running total with ^: >> >> 0 ^ 2 = 2 >> 2 ^ 1 = 0 >> 0 ^ 11 = 11 >> 11 ^ 12 = 20 >> 20 ^ 1 = 21 >> 21 ^ 11 = 2 >> 2 ^ 2 = 1 >> 1 ^ 2 = 0 >> 0 ^ 11 = 11 >> 11 ^ 1 = 12 >> >> And 12 is 5 base 3. >> >> The total will never have more digits than the biggest number. This >> is O(1) space. You have to assume base 3 conversion is a constant >> time operation, but this is pretty reasonable. >> >> If the problem changes to "all the numbers are repeated K times except >> for one, which appears only once, you can do the same thing with base >> K to get the answer. >> >> On Sep 11, 2:10 pm, Neha Singh <neha.ndelhi.1...@gmail.com> wrote: >> > You are given an array that contains integers. The integers content is >> such >> > that every integer occurs 3 times in that array leaving one integer that >> > appears only once. >> > Fastest way to find that single integer >> > eg: >> > Input: [2,1,4,5,1,4,2,2,4,1] >> > Answer: 5 >> > >> > The solution must be of O(n) time and O(1) space >> >> -- >> 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 >> algogeeks+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/algogeeks?hl=en. >> >> > -- > 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 > algogeeks+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/algogeeks?hl=en. > -- 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 algogeeks+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
