15 Puzzel Challenge Numbers for Android
The aim of the game is to move the tiles so that they are in order from 1 to 15 with the blank at the lower right.
Clicking on a tile will move it, provided it is adjacent to the blank.
It was not surprising that Sam Loyd drove the whole world crazy by his variation of the puzzle of 15. The problem that he formulated was impossible to solve. When you bought Loyd's 14-15 puzzle the empty square was positioned bottom right. The pieces were numbered in order from left to right and from top to bottom; only the pieces numbered 14 and 15 were reversed. You should re-order the pieces so all the pieces are in the correct position and the empty place should be positioned bottom right again. A slide puzzle with square pieces can only be solved when the number of exchanges necessary to solve the puzzle is even.
A nice variation of the basic slide puzzle is a slide puzzle with 15 pieces numbered form 0 (empty space) to 15 with the instruction to slide the pieces so that the sum of all rows and the sum of all columns and the sum of the diagonals equals 30. Such an ordering is called a magic square.