When an arrow is placed on a square of the board pointing north, south, east or west, the single spot means it points to the immediately adjacent cell. The 2-spot arrow points to the cell two away and the 3-spot arrow points to the cell three away. Just seven arrows of the set can be placed to map a closed circuit, as follows:
.----- ----- ----- -----
| | | | |
| 3 | 2 | | <3 |
| v | v | | |
----- ----- ----- -----
| | | | |
| | | | |
| | | | |
----- ----- ----- -----
| | | | ^ |
| | 2> | | 2 |
| | | | |
----- ----- ----- -----
| | ^ | | |
| 1> | 3 | | |
| | | | |
----- ----- ----- -----
This puzzle is to use all sixteen arrows to make a sixteen-long closed circuit. All sixteen squares must be used.
Why would this challenge be impossible if the set consisted of one 1-spot, seven 2-spot and eight 3-spot arrows?
Cinelli