@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 <[email protected] > 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 > <[email protected]>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 [email protected]. >> To unsubscribe from this group, send email to >> [email protected]. >> 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 [email protected]. > To unsubscribe from this group, send email to > [email protected]. > 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 [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/algogeeks?hl=en.
