Programmer tries to explain binary search to the police

The Picard Maneuver@startrek.website to Programmer Humor@programming.dev – 2488 points –
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I thought this had to be hyperbole, so I did the math myself. I'm assuming human history is 200,000 years as google says, and we want to narrow this down to the second the bike disappeared. also that the bike instantly vanished so there's no partially existing bike.

each operation divides the time left in half, so to get from 200k years (6.311×10^12 seconds) to 1 would take ~42.58 divisions, call it 43. even if we take a minute on average to seek and decide whether the bike is there or not it would still be less than an hour of manual sorting

hell, at 60fps it would only take another 6 divisions to narrow it down to a single frame, still under an hour

edit: to use the entire hour we'd need a couple more universes worth of video time to sort through, 36.5 billion years worth to be exact. or a measly 609 million years if we need to find that single frame at 60fps

I regularly bisect commits in the range of 200k (on the low end) for finding causes of bugs. It takes me minutes. Pretty crazy

Lemmy learns exponential math.

Mostly joking, thanks for doing the math.

History is about 10k years, the 200k years is mostly pre-history. People didn't write stuff down until they invented agriculture and needed to track trade between owners, workers, etc

True and interesting to note. OOP says 'dawn of humanity' though, not recorded history, so taking 200k as 'human history' is also valid.

Yeah, I'm used to the narrower meaning of "history", meaning recorded. I like that definition as it lets you differentiate between it and prehistory.

Well, in this case it must have been recorded on video, so could as well start recording before inventing the writing

Combine AI image/visual-pattern recognition and quantum computing, and this search could be completed before it was even started.

A minute to decide if there is a bike in the picture really ?

As a robot, finding bikes in pictures is really hard, okay

Takes time to precisely seek to each timestamp, but really I just meant that an hour was reasonable even with a lazy cop doing the search

Ever heard of a logarithm? If you haven't, you just reinvented it.

Also, your math is wrong: log base 2 of 200,000 is ~18

You did 200k years. You need to do 200k years as seconds (the 6.311e12 they mentioned). Their math is right.

Not sure why you're acting like they claimed to invent the logarithm, either...