You're given an array of distinct positive integers, candidates, and a target. Find every distinct combination of candidates that adds up exactly to target — the same candidate can be picked as many times as needed, but no two combinations in the result should be the same multiset of values. A brute-force search can find every one of these by extending every path it can think of and only checking the sum at the end (or, worse, checking it redundantly at every step without remembering it). The real win comes from carrying the running sum forward instead of recomputing it, and from cutting a branch the instant it's provably hopeless — sorting first turns "hopeless" into a single comparison instead of a search.