Taquin in c#

This repo contains the code of the famous game called Taquin. The goal of the game is to reorder the pieces in the grid using the empty square. You are allowed to "move" the empty square and exchange it with a number in the grid like this :

Before

1	2	3	4
5	2	7	8
9	10	11	12
Empty	13	14	15

After

1	2	3	4
5	2	7	8
9	10	11	12
13	Empty	14	15

Solved

1	2	3	4
5	2	7	8
9	10	11	12
13	14	15	Empty