Weight Sets for an Exact Load

Medium · Weight Sets for an Exact Load

A warehouse has weights of several kinds; their masses are listed in the array `weights` (all different). There is an unlimited supply of each kind. You need to balance a load of mass `total`: find every set of weights whose combined mass is exactly `total`. A set is defined by how many weights of each kind it contains, so `[3, 3, 4]` and `[4, 3, 3]` are the same set and must appear only once. Return the list of all sets. The sets, and the weights inside each set, may be listed in any order.…