@sunny... yeah sorry, m stupid..:) thanx On Tue, Jun 14, 2011 at 10:52 AM, sunny agrawal <sunny816.i...@gmail.com>wrote:
> @tech rascal > > 10 = 01010 > 20 = 10100 > ------------------ > xor = 11110 > = 30 > why r u getting 1 ?? > > > On Tue, Jun 14, 2011 at 2:28 AM, Supraja Jayakumar < > suprajasank...@gmail.com> wrote: > >> @Wladimir: >> Can you kindly explain the overflow and underflow you mentioned. >> >> Thanks >> Supraja J >> >> On Fri, Jun 10, 2011 at 9:58 PM, Wladimir Tavares >> <wladimir...@gmail.com>wrote: >> >>> Swapping two variables without using a temporary variable using the + >>> and -: >>> >>> x = a; >>> y = b; >>> >>> x = x + y / / x = a + b; >>> y = x - y / / y = a + b-b = a; >>> x = x - y / / x = a + b-a = b; >>> >>> y = b; >>> x = a; >>> >>> Problems with this approach: >>> 1) It can cause overflow in the operation (+) >>> 2) It can cause underflow on operation (-) >>> >>> Swapping two variables without using variables >>> Temporary using XOR: >>> >>> x = a; >>> y = b; >>> >>> x = x ^ y; >>> y = x ^ y / / y = (x xor y) xor y = x xor (y xor y) xor x = 0 = x >>> x = x ^ y / / x = (x xor y) xor x = (x xor y) xor y xor x = (x xor x) = >>> y xor y = 0 >>> >>> Note that we use some properties of XOR: >>> >>> 1) Associativity >>> 2) Commutativity >>> 3) X = X 0 XOR >>> >>> We have no problems neither underflow nor overflow! >>> >>> Wladimir Araujo Tavares >>> *Federal University of Ceará >>> >>> * >>> >>> >>> >>> >>> -- >>> 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. >>> >> >> >> >> -- >> U >> >> -- >> 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. >> > > > > -- > Sunny Aggrawal > B-Tech IV year,CSI > Indian Institute Of Technology,Roorkee > > > -- > 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.
