How the variables work on the command Add on MIPS - mips

i have a task which i cannot understand
There are 2 Mips codes which i have to write in C
a)
1.Add f,g,h
b)
Addi f,f,1
Add f,g,h
My question is on (b) Does this mean that f = (f+1) + (g+h) or f = g + h
I don't understand if the first line is overwriten by the second which makes the codes on (a) and (b) the same
Thank you for your time

addi f, f, 1 means f = f + 1, and add f, g, h means f = g + h.
The second instruction will overwrite the value of f produced in the first instruction, so the first instruction has no net effect (other than consuming time and energy) unless the symbol f has been defined to be the same register as g or h.

Related

Julia: how to optimally declare a vector containing interpolations?

I'm an economics student slowly switching from MATLAB to Julia.
Currently, my problem is that I don't know how to declare (preallocate) a vector that could store interpolations.
Specifically, when I execute something close to:
function MyFunction(i)
# x, y vectors are some functions of 'i' defined here
f = LinearInterpolation(x,y,extrapolation_bc=Line())
return f
end
g = Vector{Function}(undef, N)
for i = 1:N
g[i] = MyFunction(i)
end
I get:
ERROR: LoadError: MethodError: Cannot `convert` an object of type Interpolations.Extrapolation{Float64,1,Interpolations.GriddedInterpolation{Float64,1,Float64,Gridded{Linear},Tuple{Array{Float64,1}}},Gridded{Linear},Line{Nothing}} to an object of type Function
If I, instead of g=Vector{Function}(undef, N), declare g=zeros(N), I get a similar error message (ending with with ...Float64 rather than with ... Function).
When I, instead, declare:
g = Interpolations.Extrapolation{Float64,1,Interpolations.GriddedInterpolation{Float64,1,Float64,Gridded{Linear},Tuple{Array{Float64,1}}},Gridded{Linear},Line{Nothing}}(N)
I get:
LoadError: MethodError: no method matching Interpolations.Extrapolation{Float64,1,Interpolations.GriddedInterpolation{Float64,1,Float64,Gridded{Linear},Tuple{Array{Float64,1}}},Gridded{Linear},Line{Nothing}}(::Int64) Closest candidates are: Interpolations.Extrapolation{Float64,1,Interpolations.GriddedInterpolation{Float64,1,Float64,Gridded{Linear},Tuple{Array{Float64,1}}},Gridded{Linear},Line{Nothing}}(::Any, !Matched::Any) where {T, N, ITPT, IT, ET}
When I don't declare "g" at all, then I get:
ERROR: LoadError: UndefVarError: g not defined
Finally, when I declare:
g = Vector{Any}(undef, N)
the code works, though I'm afraid this might induce some type-change of a variable g, thereby slowing down my performance-sensitive code.
How, ideally then, should I declare g in this case?
EDIT:
In reality, my problem is a bit more complex, more like the following:
function MyFunction(i)
# x, y vectors are some functions of 'i' defined here
f = LinearInterpolation(x,y,extrapolation_bc=Line())
h = is a T-vector of some functions of x,y
A = is some matrix depending on x,y
return h, A, f
end
h = Matrix{Function}(undef, T, N)
A = zeros(T,I,N)
g = Vector{Any}(undef, N)
for i = 1:N
h[:,i], A[:,:,i], g[i] = MyFunction(i)
end
So, when I use either comprehension or broadcasting (like h, A, g = [MyFunction(i) for i in 1:N] or h, A, g = MyFunction.(1:N)), as users Benoit and DNS suggested below, the outputs of my function are 3 tuples, h, A, g, each containing {h[i], A[i], g[i]} for i=1,2,3. If I use only 1 output variable on the LHS, instead, i.e.: MyOutput = [MyFunction(i) for i in 1:N] or MyOutput[i] = MyFunction.(1:N), then MyOutput becomes a vector with N tuple entries, every tuple consisting of {h[i], A[i], g[i]} i=1,2,3,...,N. I bet there's a way of extracting these elements from the tuples in MyOutput and filling them inside h[:,i], A[:,:,i], g[i], but that seems a bit cumbersome and slow.
You could do
f = MyFunction(1)
g = Vector{typeof(f)}(undef, N)
g[1] = f
for i = 2:N
g[i] = MyFunction(i)
end
I think also map should figure out the type:
map(MyFunction, 1:N)
A simple solution is to use a comprehension:
g = [MyFunction(i) for i in 1:N]
or elegantly use the dot syntax:
g = MyFunction.(1:N)
(Credit to DNF for the dot-syntax solution suggested in the comments.)

Octave: How to sum(A .* B, 3) without expanding A .* B?

Consider the following scenario, for A with size [k, 1, m] and B with size [1, n, m], how can one get the same result as:
C = sum(A .* B, 3);
without expanding
A .* B
Because that takes way too much memory.
Something like the following loop but natively:
C = zeros(k,n);
for idx = 1:m
C += A(:,1,idx) * B(1,:,idx);
end
I guess I could also ask if there's a function like bsxfun with a "reduce"-like behavior?
Something like:
C = bsxfun_accumulate(#(a, b) a * b, A, B);
Note: by native I mean cs/cuda code-paths, or opencl code-path, or x86-sse, or plain x86 instructions. Whatever is available.
You can actually solve your problem by simply reshaping the variables A and B and applying a matrix multiply:
C = reshape(A, [], m)*(reshape(B, [], m).');
Basically, summing the results of m sets of multiplications involving k-by-1 column vectors and 1-by-n row vectors is the equivalent of multiplying a k-by-m matrix of your columns and an m-by-n matrix of your rows.

Evaluate a function using a loop Fortran 90

I'm stuck in a process where I need to compute the values of a function f[x,y,z] on a grid. Here I put how I wrote the program, only evaluating on a one-dimensional grid.
I wrote the program:
program CHISQUARE_MINIMIZATION_VELOCITY_PROFILES
use distribution
IMPLICIT none
integer, parameter :: kp=1001 ! Parameter which states the number of points on the grid.
integer, parameter :: ndata=13 ! Parameter which states the number of elements of the data file.
integer, parameter :: nconst=3 ! Fixed integer parameter.
integer i, j, n
real*8 rc0, rcf, V00, V0f, d00, d0f, rc, V0, d, z
real*8 rcr(kp), V0r(kp), d0r(kp), chisq(kp)
!Scaling radius range
rc0=0.0d-5 ! kpc
rcf=1.0d2 ! kpc
call linspace(rc0,rcf,kp,rcr)
!**************If I call like this, it works normal*****************
!CHISQUARED(1.3d0, 130.2d0, 0.12d0, 1.0d0, 1.0d0, 2.0d0, 0.0d0, 0.0d0, 1, !ndata, nconst)
! **1.27000000000000 0.745818846396887**
! Press any key to continue
!**************If I call like this, it works normal*****************
!******* Here is where my problem is****************
do j=1, kp
rc=rcr(j)
write(*,*) rc, CHISQUARED(rc, 130.2d0, 0.12d0, 1.0d0, 1.0d0, 2.0d0, 0.0d0, 0.0d0, 1, ndata, nconst)
enddo
!******* Here is where my problem is****************
end program CHISQUARE_MINIMIZATION_VELOCITY_PROFILES
I use the module where I compute the chi^2 distribution, coming from a theoretical model...
MODULE distribution
IMPLICIT NONE
CONTAINS
! I define here the chi^2 function****
real*8 function CHISQUARED(rc, V0, d, alpha, gamma, chi, a, b, n, ndata, nconst)
integer i, n, ndata, nconst
real*8 rc, V0, d
real*8 alpha, gamma, chi, a, b, s
real*8, DIMENSION(ndata,3) :: X
open(unit=1, file="data.txt")
s=0.0d0
do i=1, ndata
Read(1,*) X(i,:)
s=s+((X(i,2)-VELOCITYPROFILE(X(i,1), rc, V0, d, alpha, gamma, chi, a, b, n))/(X(i,3)))**2.0d0
end do
CHISQUARED=s/(ndata-nconst)
end function CHISQUARED
!****Here I define the model function
real*8 function VELOCITYPROFILE(r, rc, V0, d, alpha, gamma, chi, a, b, n)
integer i, n
real*8 r, rc, V0, d, alpha, gamma, chi, a, b, z
if (rc < 0.0d0 .OR. d < 0.0d0 .OR. a <0.0d0 .OR. b <0.0d0 .OR. alpha < 0.0d0 .OR. gamma <0.0d0 .OR. chi < 0.0d0 .OR. n<1 ) then
VELOCITYPROFILE=0.0d0
return
else
z=0.0d0
do i=0,n
z=z+((V0*((r/rc)**(1.5d0))*(1+a+r/rc)**(-gamma*(2*n+0.5d0)))/((a+(r/rc)**alpha)**(chi/2.0d0)))*(((b+r/rc)**gamma)/d)**i
end do
VELOCITYPROFILE=z
end if
end function VELOCITYPROFILE
END MODULE distribution
!*****************END OF THE MODULE******************************
the data.txt file is of the form
0.24 37.31 6.15
0.28 37.92 5.5
0.46 47.12 3.9
0.64 53.48 2.8
0.73 55.14 3.3
0.82 58.47 2.5
1.08 66.15 3.3
1.22 69.39 2.75
1.45 74.55 5.
1.71 77.94 2.93
1.87 81.66 2.5
2.2 86.81 3.02
2.28 90.08 2.1
2.69 94.38 3.92
2.7 95.36 1.8
In order to get several values of the function CHISQUARED, I use the subroutine linspace to generate the partition of the 1-dimensional grid
subroutine linspace(xi,xf,jmax,y)
integer jmax,j
real*8 xi,xf,y(jmax)
y=(/(xi+dble(j-1)*(xf-xi)/(dble(jmax)-1.0d0), j=1, jmax)/)
end subroutine linspace
What happens is that if in the main program, I call the function CHISQUARED like this:
CHISQUARED(1.3d0, 130.2d0, 0.12d0, 1.0d0, 1.0d0, 2.0d0, 0.0d0, 0.0d0, 1, ndata, nconst)
**1.27000000000000 0.745818846396887**
Press any key to continue
I get some finite value, like, I don't know, 0.7 or something like this. (I restricted the data file so the result won't be the one written, I just put 0.7 as an example). However, when I put it inside a loop as it is in the program written above, to get the values on the one dimensional grid, it gives me the error
**0.000000000000000E+000 NaN**
forrtl: severe (24): end-of-file during read, unit 1, file C:\Users\Ernesto Lopez Fune\Desktop\Minimize\newone\chisquarerotationcurve\data.txt
Image PC Routine Line Source
chisquarerotation 0040B889 Unknown Unknown Unknown
Press any key to continue
Can anyone recommend me what to do in this case? How to overcome this barrier?
According to your error, you reach the end of your file.
When you call your subroutine once, it's OK but in a loop, your file is read multiple times. After the first iteration, your file is read until the EOF control but for the next iteration, the program can't read anymore because it has already reached the end of the file.
You need to use the REWIND(1) statement before end function CHISQUARED. With this, the cursor will be re-positioned at the beginning of the file. Besides, I think it would be better to OPEN your file in the main program and not in a function or subroutine to avoid multiple OPEN/CLOSE.
Don't forget to CLOSE your file when you are done dealing with it.

Altering a particular column in a CSV with python3

An example. I have a CSV file laid out as such:
10,20,30,-40,50
20,30,40,-50,60
30,40,50,-60,70
Basically I need to flip the sign of the numbers in a column. Any column. In this example the signs of the 4th and 5th...
10,20,30,40,-50
20,30,40,50,-60
30,40,50,60,-70
And print them to a new file.
I can read in a CSV file, but honestly I have no idea where to go from there. Any help would be greatly appreciated.
Read in the file line by line, and split by the CSV delimiter. The order of the resulting list will be in the order of the columns (ie. splitline[0] is your first csv column, etc.). You can then write that line to a new file and modify the data accordingly. In your case I believe you want the last two value multiplied by negative 1.
Use the csv lib to parse your file:
import csv
with open("in.csv") as f, open("new.csv","w") as tmp:
r = csv.reader(f)
wr = csv.writer(tmp)
# wr.writerow(next(r)) # uncomment if file has header
# (*_ -> all but last two), (a, b -> second last and last value)
# -- == +, -+ == -
wr.writerows(_ + [-int(a), -int(b)] for *_, a, b in r:)
Input:
10,20,30,-40,50
20,30,40,-50,60
30,40,50,-60,70
Output:
10,20,30,40,-50
20,30,40,50,-60
30,40,50,60,-70
If you want the nth columns just change how you unpack:
wr.writerows([a, b, c , -int(d), -int(e)] + _ for a, b, c, d, e,*_ in r:)
^^ ^^
4th 5th
wr.writerows([-int(a),b, -int(c), d, e] + _ for a, b, c, d, e,*_ in r:)
^^ ^^
1st 3rd
If you have 41 columns and want to alter,33,39,40,41:
with open("in.csv") as f, open("out.csv","w") as tmp:
r = csv.reader(f)
wr = csv.writer(tmp)
for *_, t_3, a, b, c, d, e, t_9, ft_0, ft_1 in r:
wr.writerow(_ + [-int(t_3), a, b, c, d, e, -int(t_9), -int(ft_0), -int(ft_1)])

Code Golf: Rotating Maze

Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions.
Code Golf: Rotating Maze
Make a program that takes in a file consisting of a maze. The maze has walls given by #. The maze must include a single ball, given by a o and any number of holes given by a #. The maze file can either be entered via command line or read in as a line through standard input. Please specify which in your solution.
Your program then does the following:
1: If the ball is not directly above a wall, drop it down to the nearest wall.
2: If the ball passes through a hole during step 1, remove the ball.
3: Display the maze in the standard output (followed by a newline).
Extraneous whitespace should not be displayed.
Extraneous whitespace is defined to be whitespace outside of a rectangle
that fits snugly around the maze.
4: If there is no ball in the maze, exit.
5: Read a line from the standard input.
Given a 1, rotate the maze counterclockwise.
Given a 2, rotate the maze clockwise.
Rotations are done by 90 degrees.
It is up to you to decide if extraneous whitespace is allowed.
If the user enters other inputs, repeat this step.
6: Goto step 1.
You may assume all input mazes are closed. Note: a hole effectively acts as a wall in this regard.
You may assume all input mazes have no extraneous whitespace.
The shortest source code by character count wins.
Example written in javascript:
http://trinithis.awardspace.com/rotatingMaze/maze.html
Example mazes:
######
#o ##
######
###########
#o #
# ####### #
#### #
#########
###########################
# #
# # # #
# # # ##
# # ####o####
# # #
# #
# #########
# #
######################
Perl, 143 (128) char
172 152 146 144 143 chars,
sub L{my$o;$o.=$/while s/.$/$o.=$&,""/meg;$_=$o}$_.=<>until/
/;{L;1while s/o / o/;s/o#/ #/;L;L;L;print;if(/o/){1-($z=<>)||L;$z-2||L&L&L;redo}}
Newlines are significant.
Uses standard input and expects input to contain the maze, followed by a blank line, followed by the instructions (1 or 2), one instruction per line.
Explanation:
sub L{my$o;$o.="\n"while s/.$/$o.=$&,""/meg;$_=$o}
L is a function that uses regular expressions to rotate the multi-line expression $_ counterclockwise by 90 degrees. The regular expression was used famously by hobbs in my favorite code golf solution of all time.
$_.=<>until/\n\n/;
Slurps the input up to the first pair of consecutive newlines (that is, the maze) into $_.
L;1 while s/o / o/;s/o#/ */;
L;L;L;print
To drop the ball, we need to move the o character down one line is there is a space under it. This is kind of hard to do with a single scalar expression, so what we'll do instead is rotate the maze counterclockwise, move the ball to the "right". If a hole ever appears to the "right" of the ball, then the ball is going to fall in the hole (it's not in the spec, but we can change the # to an * to show which hole the ball fell into). Then before we print, we need to rotate the board clockwise 90 degrees (or counterclockwise 3 times) so that down is "down" again.
if(/o/) { ... }
Continue if there is still a ball in the maze. Otherwise the block will end and the program will exit.
1-($z=<>)||L;$z-2||L+L+L;redo
Read an instruction into $z. Rotate the board counterclockwise once for instruction "1" and three times for instruction "2".
If we used 3 more characters and said +s/o[#*]/ */ instead of ;s/o#/ */, then we could support multiple balls.
A simpler version of this program, where the instructions are "2" for rotating the maze clockwise and any other instruction for rotating counterclockwise, can be done in 128 chars.
sub L{my$o;$o.=$/while s/.$/$o.=$&,""/meg;$_=$o}$_.=<>until/
/;L;{1while s/o / o/+s/o#/ #/;L,L,L;print;if(/o/){2-<>&&L,L;redo}}
GolfScript - 97 chars
n/['']/~{;(#"zip-1%":|3*~{{." o"/"o "*"#o"/"# "*.#>}do}%|~.n*."o"/,(}{;\~(2*)|*~\}/\[n*]+n.+*])\;
This isn't done as well as I hoped (maybe later).
(These are my notes and not an explanation)
n/['']/~ #[M I]
{
;(# #[I c M]
"zip-1%":|3*~ #rotate
{{." o"/"o "*"#o"/"# "*.#>}do}% #drop
|~ #rotate back
.n* #"display" -> [I c M d]
."o"/,( #any ball? -> [I c M d ?]
}{ #d is collected into an array -> [I c M]
;\~(2*)|*~ #rotate
\ #stack order
}/
\[n*]+n.+*])\; #output
Rebmu: 298 Characters
I'm tinkering with with my own experiment in Code Golf language design! I haven't thrown matrix tricks into the standard bag yet, and copying GolfScript's ideas will probably help. But right now I'm working on refining the basic gimmick.
Anyway, here's my first try. The four internal spaces are required in the code as it is, but the line breaks are not necessary:
.fFS.sSC L{#o#}W|[l?fM]H|[l?m]Z|[Tre[wH]iOD?j[rvT]t]
Ca|[st[xY]a KrePC[[yBKx][ntSBhXbkY][ntSBhYsbWx][xSBwY]]ntJskPCmFkSk]
Ga|[rtYsZ[rtXfZ[TaRE[xY]iTbr]iTbr]t]B|[gA|[ieSlFcA[rnA]]]
MeFI?a[rlA]aFV[NbIbl?n[ut[++n/2 TfCnIEfLtBRchCbSPieTHlTbrCHcNsLe?sNsZ]]
gA|[TfCaEEfZfA[prT][pnT]nn]ulBbr JmoADjPC[3 1]rK4]
It may look like a cat was on my keyboard. But once you get past a little space-saving trick (literally saving spaces) called "mushing" it's not so bad. The idea is that Rebmu is not case sensitive, so alternation of capitalization runs is used to compress the symbols. Instead of doing FooBazBar => foo baz bar I apply distinct meanings. FOObazBAR => foo: baz bar (where the first token is an assignment target) vs fooBAZbar => foo baz bar (all ordinary tokens).
When the unmush is run, you get something more readable, but expanded to 488 characters:
. f fs . s sc l: {#o#} w: | [l? f m] h: | [l? m] z: | [t: re [w h] i od?
j [rv t] t] c: a| [st [x y] a k: re pc [[y bk x] [nt sb h x bk y] [nt sb
h y sb w x] [x sb w y]] nt j sk pc m f k s k] g: a| [rt y s z [rt x f z
[t: a re [x y] i t br] i t br] rn t] b: | [g a| [ie s l f c a [rn a]]]
m: e fi? a [rl a] a fv [n: b i bl? n [ut [++ n/2 t: f c n ie f l t br
ch c b sp ie th l t br ch c n s l e? s n s z]] g a| [t: f c a ee f z f
a [pr t] [pn t] nn] ul b br j: mo ad j pc [3 1] r k 4]
Rebmu can run it expanded also. There are also verbose keywords as well (first instead of fs) and you can mix and match. Here's the function definitions with some comments:
; shortcuts f and s extracting the first and second series elements
. f fs
. s sc
; character constants are like #"a", this way we can do fL for #"#" etc
L: {#o#}
; width and height of the input data
W: | [l? f m]
H: | [l? m]
; dimensions adjusted for rotation (we don't rotate the array)
Z: | [t: re [w h] i od? j [rv t] t]
; cell extractor, gives series position (like an iterator) for coordinate
C: a| [
st [x y] a
k: re pc [[y bk x] [nt sb h x bk y] [nt sb h y sb w x] [x sb w y]] nt j
sk pc m f k s k
]
; grid enumerator, pass in function to run on each cell
G: a| [rt y s z [rt x f z [t: a re [x y] i t br] i t br] t]
; ball position function
B: | [g a| [ie sc l f c a [rn a]]]
W is the width function and H is the height of the original array data. The data is never rotated...but there is a variable j which tells us how many 90 degree right turns we should apply.
A function Z gives us the adjusted size for when rotation is taken into account, and a function C takes a coordinate pair parameter and returns a series position (kind of like a pointer or iterator) into the data for that coordinate pair.
There's an array iterator G which you pass a function to and it will call that function for each cell in the grid. If the function you supply ever returns a value it will stop the iteration and the iteration function will return that value. The function B scans the maze for a ball and returns coordinates if found, or none.
Here's the main loop with some commenting:
; if the command line argument is a filename, load it, otherwise use string
m: e fi? a [rl a] a
; forever (until break, anyway...)
fv [
; save ball position in n
n: B
; if n is a block type then enter a loop
i bl? n [
; until (i.e. repeat until)
ut [
; increment second element of n (the y coordinate)
++ n/2
; t = first(C(n))
t: f C n
; if-equal(first(L), t) then break
ie f l t br
; change(C(B), space)
ch C B sp
; if-equal(third(L),t) then break
ie th L t br
; change(C(n), second(L))
ch C n s L
; terminate loop if "equals(second(n), second(z))"
e? s n s z
]
]
; iterate over array and print each line
g a| [t: f c a ee f z f a [pr t] [pn t] nn]
; unless the ball is not none, we'll be breaking the loop here...
ul b br
; rotate according to input
j: mo ad j pc [3 1] r k 4
]
There's not all that much particularly clever about this program. Which is part of my idea, which is to see what kind of compression one could get on simple, boring approaches that don't rely on any tricks. I think it demonstrates some of Rebmu's novel potential.
It will be interesting to see how a better standard library could affect the brevity of solutions!
Latest up-to-date commented source available on GitHub: rotating-maze.rebmu
Ruby 1.9.1 p243
355 353 characters
I'm pretty new to Ruby, so I'm sure this could be a lot shorter - theres probably some nuances i'm missing.
When executed, the path to the map file is the first line it reads. I tried to make it part of the execution arguments (would have saved 3 characters), but had issues :)
The short version:
def b m;m.each_index{|r|i=m[r].index(?o);return r,i if i}end;def d m;x,y=b m;z=x;
while z=z+1;c=m[z][y];return if c==?#;m[z-1][y]=" "; return 1 if c==?#;m[z][y]=?o;end;end;
def r m;m.transpose.reverse;end;m=File.readlines(gets.chomp).map{|x|x.chomp.split(//)};
while a=0;w=d m;puts m.map(&:join);break if w;a=gets.to_i until 0<a&&a<3;
m=r a==1?m:r(r(m));end
The verbose version:
(I've changed a bit in the compressed version, but you get the idea)
def display_maze m
puts m.map(&:join)
end
def ball_pos m
m.each_index{ |r|
i = m[r].index("o")
return [r,i] if i
}
end
def drop_ball m
x,y = ball_pos m
z=x
while z=z+1 do
c=m[z][y]
return if c=="#"
m[z-1][y]=" "
return 1 if c=="#"
m[z][y]="o"
end
end
def rot m
m.transpose.reverse
end
maze = File.readlines(gets.chomp).map{|x|x.chomp.split(//)}
while a=0
win = drop_ball maze
display_maze maze
break if win
a=gets.to_i until (0 < a && a < 3)
maze=rot maze
maze=rot rot maze if a==1
end
Possible improvement areas:
Reading the maze into a clean 2D array (currently 55 chars)
Finding and returning (x,y) co-ordinates of the ball (currently 61 chars)
Any suggestions to improve are welcome.
Haskell: 577 509 527 244 230 228 chars
Massive new approach: Keep the maze as a single string!
import Data.List
d('o':' ':x)=' ':(d$'o':x)
d('o':'#':x)=" *"++x
d(a:x)=a:d x
d e=e
l=unlines.reverse.transpose.lines
z%1=z;z%2=l.l$z
t=putStr.l.l.l
a z|elem 'o' z=t z>>readLn>>=a.d.l.(z%)|0<1=t z
main=getLine>>=readFile>>=a.d.l
Nods to #mobrule's Perl solution for the idea of dropping the ball sideways!
Python 2.6: ~ 284 ~ characters
There is possibly still room for improvement (although I already got it down a lot since the first revisions).
All comments or suggestions more then welcome!
Supply the map file on the command line as the first argument:
python rotating_maze.py input.txt
import sys
t=[list(r)[:-1]for r in open(sys.argv[1])]
while t:
x=['o'in e for e in t].index(1);y=t[x].index('o')
while t[x+1][y]!="#":t[x][y],t[x+1][y]=" "+"o#"[t[x+1][y]>" "];x+=1
for l in t:print''.join(l)
t=t[x][y]=='o'and map(list,(t,zip(*t[::-1]),zip(*t)[::-1])[input()])or 0
C# 3.0 - 650 638 characters
(not sure how newlines being counted)
(leading whitespace for reading, not counted)
using System.Linq;
using S=System.String;
using C=System.Console;
namespace R
{
class R
{
static void Main(S[]a)
{
S m=S.Join("\n",a);
bool u;
do
{
m=L(m);
int b=m.IndexOf('o');
int h=m.IndexOf('#',b);
b=m.IndexOf('#',b);
m=m.Replace('o',' ');
u=(b!=-1&b<h|h==-1);
if (u)
m=m.Insert(b-1,"o").Remove(b,1);
m=L(L(L(m)));
C.WriteLine(m);
if (!u) return;
do
{
int.TryParse(C.ReadLine(),out b);
u=b==1|b==2;
m=b==1?L(L(L(m))):u?L(m):m;
}while(!u);
}while(u);
}
static S L(S s)
{
return S.Join("\n",
s.Split('\n')
.SelectMany(z => z.Select((c,i)=>new{c,i}))
.GroupBy(x =>x.i,x=>x.c)
.Select(g => new S(g.Reverse().ToArray()))
.ToArray());
}
}
}
Reads from commandline, here's the test line I used:
"###########" "#o #" "# ####### #" "#### #" " #########"
Relied heavily on mobrule's Perl answer for algorithm.
My Rotation method (L) can probably be improved.
Handles wall-less case.