Installation instructions (simple):

1. cd into this directory
2. mkdir build
3. cd build
4. cmake ../
5. make

To run exemplary puzzle:
"./main ../examples/sudoku_e1.txt"


Remark:
This algorithm is not perfect. It makes use of good guesses at certain steps and proceeds recursively until a solution is found, the number of guesses exceeds three or there 
are no more further possibilities for setting numbers.