When One Letter Changes Everything: The Algorithms Behind Every Spell Checker
In 1961, Les Earnest at MIT built the first spell checker as part of a cursive handwriting recognition system. His program used a list of just 10,000 common words, comparing each handwritten recognition result against the dictionary. The system was rudimentary, but it established a pattern that would repeat for decades: spell checking is fundamentally a string matching problem, and the challenge lies in making it fast enough to be useful. ...