Solves countdown numbers game

Finds if is it possible to calculate target number from specified numbers using addition, subtraction, multiplication and division, if not gives the closest solution from target. Find and displays all possible solutions, max 1000. User can enter a maximum of 9 numbers (finding solution fron 9 diferent numbers will take a long time).

App only looks for integer solutions but an intermediate point in the solution can be real, example app will find (7/2+10)*6=81.

App has several codepaths: native C or optimizations for special cases like only integer division or code optimized for search with one repeating number.

User can set number of threads app can use and code version java or native C in options menu.

App has copy to clipboard button and auto copy option.