# Sokoban Level 3g

Sokoban Level 3g is one of the new maps for Sokoban in some variants of NetHack. It may appear as the second level of Sokoban in UnNetHack, and may appear as a possible third floor map in EvilHack and Hack'EM; in Hack'EM, this map is named "Back Alley Cliche" in the Sokoban level data. It has 9 boulders and 9 holes, leaving no spare boulders.

In UnNetHack, this level may be flipped horizontally or vertically like all Sokoban levels.

```           ----        0 boulder
---------|>.|        ^ hole
---...|...--0.|---     > starting position/downstairs
|..00.|.....0.|..|     < upstairs
|.|...|...--0.^..|     # iron bars
|.|...|.00.|..--^|
|.|.----.|.--#--^|---
|.|0.|--.|..|<|..|..|
|.|..|....|.|.|..^..|
|.....0...|.|.--#--^--
|.|..---.--.|..|..|..|
|.----......#..#..^..|
|......-----|..|^-----
--------    |^--..|
|..^..|
|..----
----
```

## Strategy

The following solution may not be very fast or organized. Improvements welcome. Like all Sokoban levels it can be solved without making any boulders 'stick'.

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 hole (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 hole.

First, rearrange the boulders to make some room to push around the two boulders in the entrance chamber:

```           ----        D llll
---------|@.|        F dddd
---...|...--A.|---     I lll
|..BC.|.....D.|..|     H uuu
|.|...|...--E.^..|     I u
|.|...|.FG.|..--^|     F llll l
|.|.----.|.--#--^|---  G lddd dl
|.|H.|--.|..|<|..|..|  D dddd dd
|.|..|....|.|.|..^..|
|.....I...|.|.--#--^--
|.|..---.--.|..|..|..|
|.----......#..#..^..|
|......-----|..|^-----
--------    |^--..|
|..^..|
|..----
----
```

Deal with the two boulders in the entrance chamber:

```           ----        A dlll ld
---------|>.|        E ulll lrrr rrdr*
---...|...--A.|---     A urrr rrdr rrd*
|..BC.|.......|..|
|.|H..|...--E.^..|
|.|...|....|..--^|
|.|.----.|.--#--^|---
|.|..|--.|..|<|..|..|
|.|I.|..@.|.|.|..^..|
|..F...GD.|.|.--#--^--
|.|..---.--.|..|..|..|
|.----......#..#..^..|
|......-----|..|^-----
--------    |^--..|
|..^..|
|..----
----
```

The middle passage enables the next four boulders to be pushed into the holes:

```           ----        D ____ ___ uuuu uurr rrrd rrrd d*
---------|>.|        G r___ ___ uuuu uurr rrrd rrrd dddr*
---...|...--..|---     F rrrr r__ uuuu uurr rrrd rrrd dddr rrd*
|..BC.|.......|..|     I drrr rr_ uuuu uurr rrrd rrrd dddr rrdd dl*
|.|H..|...--....@|
|.|...|....|..--.|
|.|.----.|.--#--^|---
|.|..|--.|..|<|..|..|
|.|I.|....|.|.|..^..|
|..F...GD.|.|.--#--^--
|.|..---.--.|..|..|..|
|.----......#..#..^..|
|......-----|..|^-----
--------    |^--..|
|..^..|
|..----
----
```

Rearranging the clump of three boulders allows them to fill the final holes:

```           ----        C d
---------|>.|        B r
---...|...--..|---     H dddd d___ rrrr ruuu uuur rrrr drrr dddd rrrd ddll ld*
|..BC.|.......|..|     B lddd ddd_ rrrr ruuu uuur rrrr drrr dddd rrrd ddll lddd l*
|.|H..|...--.....|     C lddd dd__ rrrr ruuu uuur rrrr drrr dddd rrrd ddll lddd lllu*
|.|...|....|..--.|
|.|.----.|.--#--.|---
|.|..|--.|..|<|..|..|
|.|..|....|.|.|.....|
|.........|.|.--#--.--
|.|..---.--.|..|..|..|
|.----......#..#...@.|
|......-----|..|^-----
--------    |^--..|
|..^..|
|..----
----
```

The level is now complete:

```           ----
---------|>.|
---...|...--..|---
|.....|.......|..|
|.|...|...--.....|
|.|...|....|..--.|
|.|.----.|.--#--.|---
|.|..|--.|..|<|..|..|
|.|..|....|.|.|.....|
|.........|.|.--#--.--
|.|..---.--.|..|..|..|
|.----......#..#.....|
|......-----|..|.-----
--------    |.--..|
|@....|
|..----
----
```