This project solves the following seemingly simple task:
Find all combinations of 1, 2, 3, 4, 5, 6, 7, 8, 9 which evaluates into 100.
You can insert operators +, *, - and concat between numbers.
Order of numbers is not important, but each number shold appear once and only once.
1 concat 2 = 12.
On my hardware (4-core Intel Core i7 870@2.93 GHz with HyperThreading enabled) the program executes for about 4.5 hours. It uses only small amount of RAM (about 15 MiB).
Hundreds is a competing software.