This C++11 code of Knuth Algorith X with Doubly Linked Lists, called DLX.

It prints out all solutions to Pentomino puzzle for a NxM rectangular board.

In each solution, board tiles are numbered 0 to 59.

Output example:

0 1 7 13 14 Z
2 8 9 15 16 W
3 4 5 10 11 P
6 12 18 19 24 Y
17 21 22 23 29 T
20 25 26 27 32 X
28 34 35 41 47 N
30 36 42 43 44 V
31 33 37 38 39 U
40 45 46 52 53 F
48 49 50 51 54 L
55 56 57 58 59 I

0 6 7 8 14 Z
1 2 3 4 5 I
9 10 11 15 17 U
12 13 18 19 24 P
16 21 22 23 29 F
20 25 26 27 32 X
28 33 34 38 39 W
30 36 42 48 49 L
31 37 43 44 45 V
35 40 41 47 53 Y
46 52 57 58 59 T
50 51 54 55 56 N

0 6 7 8 14 Z
1 2 3 4 9 Y
5 10 11 15 16 W
12 13 18 19 24 P
17 23 29 35 41 I
20 25 26 27 32 X
21 22 28 33 34 U
30 31 37 38 39 N
36 42 48 54 55 L
40 44 45 46 52 T
43 49 50 51 56 F
47 53 57 58 59 V

0 6 7 8 14 Z
1 2 3 4 9 Y
5 10 11 15 16 W
12 13 18 19 24 P
17 21 22 23 29 T
20 25 26 27 32 X
28 34 35 41 47 N
30 36 42 43 44 V
31 33 37 38 39 U
40 45 46 52 53 F
48 49 50 51 54 L
55 56 57 58 59 I

Found 2339 solutions
Matrix generation time: 0.0122784 seconds
Elapsed time: 27.5229 seconds