Comedy of coding errors

Nerd alert. You will probably enjoy this post if and only if you are a fellow programmer.

There's a fair amount of horrible legacy code here at my new company. It is nobody's fault -- apparently it was written by an intern at another company, then bought by my company. Which is great, because I can loudly ridicule this code without fear of offending anyone. My cubicle-mate is the senior Java developer. Together, the two of us ARE the entire Java team right now; other people here are coding a little bit of Java, but we're the experts and the commerce project is owned exclusively by us.

I ran into a beautifully horrifying bit of code today. First it gathers a list of objects from a table. Then it iterates over each object, seeing whether the object is "authorized"... and then it removes the object from the array. Not only is this inefficient to begin with -- they should have just filtered out the unauthorized objects in the original query -- but they keep rearranging the entire array every time an object is removed. Like this:

1 2 3 4 5
(object 2 is unauthorized)
1 3 4 5

Obviously this runs in O(n^2) time, when it could easily run in O(n) time just by adding a second array.

Wait, it gets worse. I'm trying to fix it, and I realize the same code that kicks out unauthorized objects appears to be in there TWICE... it's iterating over the array twice and doing approximately the same thing each time. I don't know why, but it appears to have something to do with the magic number "50" that keeps showing up in the code. As in:

for (all items) {
 if (curItem < 50) {
      do one thing
 }
}
for (all items) {
 if (curItem > 50) {
      do almost the same thing, but slightly different
 }
}

Dear God, WHY? What does 50 mean? I don't know, the code doesn't give me a clue. You would think 50 is something arbitrary like the number of items displayed per page, but no... only 12 items are displayed per page. ARGH ARGH ARGH ARGH ARGH.

The bright side is that I don't think I've actually had to solve a genuine programming logic puzzle in like this for many months -- I can't remember a single example at DMi. This is fun! When I'm done, the code will run much faster. And there's probably hundreds of examples of this crummy design lurking around, waiting to be fixed.

Yay job security!