Just came across an old GIF of mine.
When I first started learning C, my first real program was a brute-force password cracker. It wasn't the fastest and didn't have a practical purpose, because it didn't crack a password of any specific program, just a known string.
Uuuh, it even outputs to the screen, just like in the movies! =)
Yeah. I thought that was awesome when I wrote it. The program has two displays, one where it shows every guess, and another where it shows how many guesses it has made so far. Having just ran it with the display disabled, the execution time is...
Matched "jacob" with 4589756 tries, in 1288/ms
That's a big difference, so that fancy display actually does more harm than its worth :]