Let's say we have some function,
float distance(String a, String b) { /*...*/ }
to find the Levenshtein distance between two strings, and we have a large array of strings.
String[] strings = new String[1_000_000];
What would be an acceptable approach to map a String a to its closest match (i.e., the String b that produces the lowest result of distance(a, b)) in that array? This will need to be done often, and so going through the entire array every time would not make sense.
Of course, strings need not be an array.
