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.
