It's the property of XOR :) What's 5 XOR 5?
If the boy is happy then pile A = pile B, therefore pile A XOR pile B = 0. Sent from my iPhone On 2011-05-10, at 7:26 AM, Marcelo Ramires <[email protected]> wrote: > Right, I didn't ask how does one figure out that it's about XOR, because this > I've figured out too when I was solving, what I didn't know and surprised me > that everybody else knew is: > > 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 did't know this property of XOR, must be because I've never worked with XOR > in integers, but I'd say that if I had only used it a little I wouldn't catch > it quickly... > > On Mon, May 9, 2011 at 6:01 PM, Reniery O'Hara <[email protected]> wrote: > Hi, > One could come to this solution by understanding the Sean adding skills, > 1100 > + 0101 > ------ > 1001 > compare this with the XOR truth table and you will have a match. > As others posted before practice will help us to see these patterns while > reading the problems. > > (Personally I didn't use an explicit integer XOR, I used mod 2) > > > > On Mon, May 9, 2011 at 4:59 PM, rahul raghavendra <[email protected]> > wrote: > u can do a lot of stuff with the bitwise operators , u just gotta experiment > with it > > > On Tue, May 10, 2011 at 2:21 AM, Morgan Bauer <[email protected]> wrote: > XOR is the bread and butter of Symmetric Cryptography. > ~mhb > > On Mon, May 9, 2011 at 4:44 PM, Marcelo Ramires > <[email protected]> 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 <[email protected]> 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 <[email protected]> > >> 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 [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. > >> > >> > >> > >> -- > >> 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 [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. > > > > -- > > 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. > > > > -- > 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. > > > > > -- > K.Rahul ) > > > > -- > 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. > > > > -- > Reniery > > -- > 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. > > -- > 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. -- You received this message because you are subscribed to the Google Groups "google-codejam" group. 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