An alternative use for XORing numbers greater than 1: The game of Nim. I think this is where I first learned about the operation. On 9 May 2011 21:44, "Marcelo Ramires" <marcelo.f.rami...@gmail.com> wrote: > I understood how to solve this, but *how does one come to this solution ?* > * > If the xor of all numbers is zero, you can pick any candy, and the xor to > this number is going to be equal to the xor from the rest of them.* > > I get this, if I have 9 numbers with XOR 3, XORing it with 3 will get me > zero. > > How has everybody thought of this at the same time ? have I skipped a logics > class ? is this concept so disseminated among coders ? > > I had never XORed nubmers before this code jam, only booleans, and I didn't > know you could. > > As a side questions, can anybody tell me any alternative uses for XORing > integers other than 1 and 0 ? > > Thanks! > > Marcelo Ramires > > On Sun, May 8, 2011 at 1:50 AM, vivek dhiman <vivek4dhi...@gmail.com> wrote: > >> Lucky! >> >> You are right. >> >> if xor of two lists is same. (say xor1 = xo2) >> >> So the exor of these two wil be 0 (xor (xor1,xor2) = 0) >> Or in other words lists can be divided if the xor of all the elements is >> zero. >> >> :) >> >> >> >> >> On Sun, May 8, 2011 at 8:17 AM, keshav agarwal <keshav...@gmail.com >wrote: >> >>> please tell me of my logic was correct or i just got lucky to get it >>> correct >>> >>> if xor to a list of nos. is zero only then the division is possible >>> in this case patrick can be given the one candy with lowest value while >>> sean keeps the rest >>> >>> if xor(n nos.)=0 >>> then (nth no.) xor (xor of n-1 nos.)=0 >>> >>> so patrick gets the nth candy and sean keeps the rest >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "google-codejam" group. >>> To post to this group, send email to google-code@googlegroups.com. >>> To unsubscribe from this group, send email to >>> google-code+unsubscr...@googlegroups.com. >>> For more options, visit this group at >>> http://groups.google.com/group/google-code?hl=en. >>> >> >> >> >> -- >> Regards >> Vivek Dhiman >> >> -- >> You received this message because you are subscribed to the Google Groups >> "google-codejam" group. >> To post to this group, send email to google-code@googlegroups.com. >> To unsubscribe from this group, send email to >> google-code+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/google-code?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups "google-codejam" group. > To post to this group, send email to google-code@googlegroups.com. > To unsubscribe from this group, send email to google-code+unsubscr...@googlegroups.com. > For more options, visit this group at http://groups.google.com/group/google-code?hl=en. >
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