@all above you are suggesting brute force solution and have a look at the constraints and time limits which are too strict so such solution would work over here i need a DP approach. @vandana we can't make hash because of the high value of N. @ramindar actually not only reverse there exist all the permutation of each number. for 123 132 213 231 312 321 all exist. Thanks for you response.
On Sat, Apr 21, 2012 at 2:02 AM, Ramindar Singh <ramin...@gmail.com> wrote: > Just to add to Vandana > > certain observations like > > 1) consider 1,2,3,4..... 9 as 01,02,03,04...... 09 so the reverse of the > strings are also present in the answer ie 10,20,30,40.... 90 > 2) when you traverse the numbers like 11,12,13,14.... 19 and you dont find > any PDS number you are omitting the numbers 21,31,41,51.... 91 so you need > not to verify on these numbers > Also in the next traversal you are not checking it for 21 as explained > and for 22,23,24.... 29 you would omit the numbers 32,42,52.... 92 > In the next line for 33,34,35,36....39, we have a PDS number 36 and also > we have its reverse 63 as a PDS. > > So by the time you reach the 9* line you just need to verify the 99 digit > as you have verified the others earlier. > Hope this helps :) > > > Thanks > Ramindar Singh > > On Friday, 20 April 2012 23:49:48 UTC+5:30, amrit harry wrote: >> >> http://www.codechef.com/**APRIL12/problems/PDSNUM<http://www.codechef.com/APRIL12/problems/PDSNUM> >> >> > -- > You received this message because you are subscribed to the Google Groups > "Algorithm Geeks" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/algogeeks/-/m1GvKl8FWcMJ. > > 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. > -- AMRIT -- 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.
