Showing archive results for 2014

Inspired by the Little Program which enumerates set partitions, I decided to do the binomial coefficients this week. In other words, today's Little Program generates all subsets of size k from a set of size n. As before, the key is to interpret a recurrence combinatorially. In general, when a recurrence is of the form A + B, it means that at th...

There's a DLL in the system directory called , and from its name, you might think that it is the Microsoft Visual C/C++ Run-Time library. That is a perfectly reasonable guess. But it would also be wrong. The Microsoft Visual C/C++ Run-Time libraries go by names like or or or , and the debugging versions have a in there, too. And like MFC,...

Why does hate ? Because everybody hates ! Commenter kero claims that it's "easy to fix" the problem with and . You just remove the style temporarily, then do the normal , then restore the style. The question is then why simply doesn't do this. The question assumes that the described workaround actually works. It may work in limited situati...

They get cleaned up eventually.

There is an oft-abused program named . Why does its name end in ? Why not just call it ? (I will for the moment ignore the rude behavior of calling people stupid under the guise of asking a question.) Because there needed to be a way to distinguish the 16-bit version from the 32-bit version. Windows 95 had both (the 16-bit version) and (...

Today's Little Program shows one way you can implement a better version of . Our first version doesn't use at all. Start with the scratch program and make the following changes: Most of this program was stolen from my scroll bar series. The interesting new bits are that you can add one new item by hitting 1, or you can add ten thousand item...

"How do I destroy a window that belongs to another process?" The function will not destroy windows that belong to another thread, much less another process. The best you can do is post a message to the window to ask it nicely. The function response to the message by destroying the window, but the window is free to add a custom handler for th...

When an application crashes with an access violation, the error message says something like The instruction at "XX" referenced memory at "YY". The memory could not be "read". Why is the operation in quotation marks? Is this some sort of euphemism? The odd phrasing is a consequence of globalization. The operation name is a verb in the infinitive...

A few years after I posted this story, the security team received something very similar. If have found that if you call the XYZ function (whose last parameter is supposed to be a pointer to a ) and instead of passing a value pointer to a , you pass , then you can trigger an access violation in the XYZ function. The XYZ function does not check ...

Some time ago, there was a performance-related bug that went something like this: mm/dd/yy Created by bob The attached file contains a dataset that takes a very long time to process. The engineer who fixed the problem decided to take the cryptic approach: mm/dd/yy Resolved as fixed by alice It got better. It was a common practice during hig...