Problem 105

Special subset sums: testing

Let S(A) represent the sum of elements in set A of size *n*. We shall call it a special sum set if for any two non-empty disjoint subsets, B and C, the following properties are true:

- S(B) S(C); that is, sums of subsets cannot be equal.
- If B contains more elements than C then S(B) S(C).

For example, {81, 88, 75, 42, 87, 84, 86, 65} is not a special sum set because 65 + 87 + 88 = 75 + 81 + 84, whereas {157, 150, 164, 119, 79, 159, 161, 139, 158} satisfies both rules for all possible subset pair combinations and S(A) = 1286.

Using sets.txt
(right click and "Save Link/Target As..."), a 4K text file with
one-hundred sets containing seven to twelve elements (the two examples
given above are the first two sets in the file), identify all the
special sum sets, A_{1}, A_{2}, ..., A_{k}, and find the value of S(A_{1}) + S(A_{2}) + ... + S(A_{k}).

**
These problems are part of
Project Euler
and are licensed under
CC BY-NC-SA 2.0 UK
**