So, what was fishy in this code -- except for my typo in the second for-loop -- was the assignment
i = i-- The correct version of the first for-loop would simply have had "i--" or "--i", instead of "i=i--". If you have an assignment j = i--, it's clear what's going to happen: j gets the value of i, and after that i is decremented. In this case it's not so clear what is supposed to happen. In C (or C++), if i==n, then after executing i=i--, i turns out to have the value n-1. The funny thing is that in Java i will still have the value n. I am tempted to think that C does it right and Java does it wrong, so I'm tempted to see this as a bug in the Java language (I also wonder if all compilers produce the same code). The Java language specification does not seem to specify unambiguously how i=i-- should be interpreted. (http://java.sun.com/docs/books/jls/second_edition/html/expressions.doc.html#39438) Hans ----- Original Message ----- From: "Geuns, Hans" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, May 09, 2002 10:35 AM Subject: [cscie119] Bug of the month > What is the complexity of the following code (how fast does it run)? > > for (int i=n; i > 0; i = i--) > for (int j=1; j < 1; j = j*2) > print(j); > > > (Students who attended section yesterday are not elligible for prizes. > Thanks to Tom Faiano for pointing out that there was something funny with > this code fragment from the practice final.) > > Hans > >
