Quora: Which Computer Algorithms are Practical in Real Life?

In real life, (not that I am familiar with a fake one,) Binary search, is a surprisingly useful algorithm.

An example of how this algorithm can be applied is studying for the SAT. Imagine you bought 5000 index cards, alphabetically sorted, with vocabulary words on them. Then, just as you were about to start studying, you got an alert that the definition for “sisyphean” was incorrect. You would know how to quickly remove it from the deck, while most “normal people” would sit there sifting through all 5000 index cards!

A binary search could be applied to cut the deck in half. Once you select the half where the “s” words are, you could continue this process until you find your card. On average you would spend O(log n) finding your card vs. O(n) for someone that had to scan the whole deck sequentially!