Collecting Marbles

This is one of the new possible maps for Sokoban Level 1 in Hack'EM. It has 21 boulders and 18 holes, leaving 3 spare boulders.

  ------------------------ 0 boulder
  |..^^^^^^^^^^^^^^^^^^..| ^ hole
  |..-------------------.| > starting position/downstairs
----.--   ----         |.| + door
|.0...-----..|         |.|
|......0..00.|         |.|
--.0.....|.0.|         |.|
 --....0.|...|         |.|
  |0----.--.-|   ------|.|
 --.0.--..0..| --|.....|.|
 |...........| |.+.....|.|
 |0.0---.--.-| |-|.....|.|
 |...|.0..0..| |.+.....+.|
--.---..0..0.| |-|.....|--
|.0..0.0.0.0.| |.+.....|
|.>..|.......| --|.....|
--------------   -------

Strategy

All boulders are replaced by letters so they can be referred to. Moving the boulders is shortened to r for right, l for left, u for up, d for down. An asterisk is used to denote the last move filled a pit (and thus removed the boulder from the game). So "N ddrr*" means move boulder N two times down and two times to the right into a pit.

  ------------------------ A r
  |..^^^^^^^^^^^^^^^^^^..| D rruu ur*
  |..-------------------.| H lllu uuur r*
----.--   ----         |.| E uuru uurr r*
|.D...-----..|         |.| F uuuu ruuu rrrr*
|......H..JK.|         |.| G luuu uruu urrr r*
--.E.....|.L.|         |.| I llll uuur uuur rrrr r*
 --....I.|...|         |.| C uulu uuuu ruuu rrrr rrr*
  |F----.--.-|   ------|.|
 --.G.--..M..| --|.....|.|
 |...........| |.+.....|.|
 |B.C---.--.-| |-|.....|.|
 |...|.N..O..| |.+.....+.|
--.---..P..Q.| |-|.....|--
|.A..R.S.T.U.| |.+.....|
|.>..|.......| --|.....|
--------------   -------

  ------------------------ L l
  |.........^^^^^^^^^^^..| K d
  |..-------------------.| J llll lluu uurr rrrr rr*
----.--   ----         |.| K ulll llll uuuu rrrr rrrr r*
|.....-----..|         |.| L ulll lllu uuur rrrr rrrr r*
|.........JK.|         |.| M lluu uull lluu uurr rrrr rrrr r*
--.......|.L.|         |.|
 --......|...|         |.|
  |.----.--.-|   ------|.|
 --...--..M..| --|.....|.|
 |...........| |.+.....|.|
 |B..---.--.-| |-|.....|.|
 |...|.N..O..| |.+.....+.|
--.---..P..Q.| |-|.....|--
|..A.R.S.T.U.| |.+.....|
|.>..|.......| --|.....|
--------------   -------

  ------------------------ U l
  |.............^^^^^^^..| Q uuuu uuuu llll lllu uuur rrrr rrrr rrr*
  |..-------------------.| O ruuu uuuu llll lllu uuur rrrr rrrr rrrr*
----.--   ----         |.| U uuru uuuu uull llll luuu urrr rrrr rrrr rrr*
|.....-----..|         |.| T ruur uuuu uuul llll lluu uurr rrrr rrrr rrrr r*
|............|         |.| P uuuu uuuu llll uuuu rrrr rrrr rrrr rrrr*
--.......|...|         |.| N ruuu uuuu ulll luuu urrr rrrr rrrr rrrr rr*
 --......|...|         |.| S uuru uuuu uuul lllu uuur rrrr rrrr rrrr rrrr r*
  |.----.--.-|   ------|.|
 --...--.....| --|.....|.|
 |...........| |.+.....|.|
 |B..---.--.-| |-|.....|.|
 |...|.N..O..| |.+.....+.|
--.---..P..Q.| |-|.....|--
|..A.R.S.T.U.| |.+.....|
|.>..|.......| --|.....|
--------------   -------