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Let’s say I have a Java ArrayList, that is sorted. Now I would like to find the index of value x. What would be the fastest (without more than 30 lines of code) way to do this? Use of the IndexOf() method? Iterate through all values in a simple for loop? Use of some cool algorithm? We are talking about around let’s say 50 integer keys.
Binary search, but since it’s only 50 items, who cares (unless you have to do it millions of times)? A simple linear search is simpler and the difference in performance for 50 items is negligible.
Edit: You could also use the built-in java.util.Collections binarySearch method. Be aware, that it will return an insertion point even if the item isn’t found. You may need to make an extra couple of checks to make sure that the item really is the one you want. Thanks to @Matthew for the pointer.