I have written a computer program which solves Sudoku puzzles

[KrazyHorse]

Point at me and laugh, for I am sad.

[KrazyHorse]

function square, r, c
s = 3*floor(r/3.0) + floor(c/3.0)
return, s
end

function delta, a, b
s = 0
if (a EQ b) then begin
	s = 1
endif
return, s
end

function eliminator, poss
a = 0L
while a LE 100L do begin
	totalposs0 = total(poss)
	sumvals = total(poss, 3)
	for r = 0, 8 do begin
		for c = 0, 8 do begin
			if (sumvals[r, c] EQ 0) then begin
				poss = fltarr(9, 9, 9)
				a = a + 10000L
			endif
			if (sumvals[r, c] EQ 1) then begin
				for j = 0, 8 do begin
					if (poss[r, c, j] EQ 1) then begin
						for rprime = 0, 8 do begin
							poss[rprime, c, j] = delta(r, rprime)
						endfor
						for cprime = 0, 8 do begin
							poss[r, cprime, j] = delta(c, cprime)
						endfor
						for rprime = 0, 8 do begin
							for cprime = 0, 8 do begin
								if (square(r, c) EQ square(rprime, cprime)) then begin
									poss[rprime, cprime, j] = poss[rprime, cprime, j] * delta(r, rprime) * delta(c, cprime)
								endif
							endfor
						endfor
					endif
				endfor
			endif
		endfor
	endfor
	sumrows = total(poss, 1)
	for c = 0, 8 do begin
		for j = 0, 8 do begin
			if (sumrows[c, j] EQ 0) then begin
				poss = fltarr(9, 9, 9)
				a = a + 10000L
			endif
			if (sumrows[c, j] EQ 1) then begin
				for r = 0, 8 do begin
					if (poss[r, c, j] EQ 1) then begin
						for jprime = 0, 8 do begin
							poss[r, c, jprime] = delta(j, jprime)
						endfor
					endif
				endfor
			endif
		endfor
	endfor
	sumcols = total(poss, 2)
	for r = 0, 8 do begin
		for j = 0, 8 do begin
			if (sumcols[r, j] EQ 0) then begin
				poss = fltarr(9, 9, 9)
				a = a + 10000L
			endif
			if (sumcols[r, j] EQ 1) then begin
				for c = 0, 8 do begin
					if (poss[r, c, j] EQ 1) then begin
						for jprime = 0, 8 do begin
							poss[r, c, jprime] = delta(j, jprime)
						endfor
					endif
				endfor
			endif
		endfor
	endfor
	sumsqrs = fltarr(9, 9)
	for j = 0, 8 do begin
		for r = 0, 8 do begin
			for c = 0, 8 do begin
				sqr = square(r, c)
				sumsqrs(sqr, j) = sumsqrs(sqr, j) + poss[r, c, j]
			endfor
		endfor
	endfor
	for sqr = 0, 8 do begin
		for j = 0, 8 do begin
			if (sumsqrs[sqr, j] EQ 0) then begin
				poss = fltarr(9, 9, 9)
				a = a + 10000L
			endif
			if (sumsqrs[sqr, j] EQ 1) then begin
				for r = 0, 8 do begin
					for c = 0, 8 do begin
						if (square(r, c) EQ sqr) then begin
							if (poss[r, c, j] EQ 1) then begin
								for jprime = 0, 8 do begin
									poss[r, c, jprime] = delta(j, jprime)
								endfor
							endif
						endif
					endfor
				endfor
			endif
		endfor
	endfor
	totalposs1 = total(poss)
	if (totalposs1 EQ totalposs0) then begin
		a = a + 10000L
	endif
	a = a + 1
endwhile
return, poss
end

pro solver
n = 28
;n is the number of values pre-determined by the person who wrote the puzzle
grow = intarr(n)
gcol = intarr(n)
gval = intarr(n)
;given values for given row and given column
;note that row and column numbering begins at 0, but gval must be an integer from 1 to 9
grow[0] = 0
gcol[0] = 0
gval[0] = 9
grow[1] = 0
gcol[1] = 1
gval[1] = 5
grow[2] = 0
gcol[2] = 6
gval[2] = 6
grow[3] = 0
gcol[3] = 7
gval[3] = 7
grow[4] = 1
gcol[4] = 5
gval[4] = 7
grow[5] = 1
gcol[5] = 6
gval[5] = 3
grow[6] = 1
gcol[6] = 7
gval[6] = 1
grow[7] = 2
gcol[7] = 0
gval[7] = 8
grow[8] = 2
gcol[8] = 3
gval[8] = 5
grow[9] = 2
gcol[9] = 4
gval[9] = 6
grow[10] = 2
gcol[10] = 5
gval[10] = 1
grow[11] = 3
gcol[11] = 0
gval[11] = 2
grow[12] = 3
gcol[12] = 1
gval[12] = 3
grow[13] = 4
gcol[13] = 2
gval[13] = 9
grow[14] = 4
gcol[14] = 6
gval[14] = 1
grow[15] = 5
gcol[15] = 7
gval[15] = 3
grow[16] = 5
gcol[16] = 8
gval[16] = 7
grow[17] = 6
gcol[17] = 3
gval[17] = 1
grow[18] = 6
gcol[18] = 4
gval[18] = 4
grow[19] = 6
gcol[19] = 5
gval[19] = 5
grow[20] = 6
gcol[20] = 8
gval[20] = 9
grow[21] = 7
gcol[21] = 1
gval[21] = 9
grow[22] = 7
gcol[22] = 2
gval[22] = 4
grow[23] = 7
gcol[23] = 3
gval[23] = 2
grow[24] = 8
gcol[24] = 1
gval[24] = 8
grow[25] = 8
gcol[25] = 2
gval[25] = 5
grow[26] = 8
gcol[26] = 7
gval[26] = 2
grow[27] = 8
gcol[27] = 8
gval[27] = 1
poss = intarr(9, 9, 9)
for r = 0, 8 do begin
	for c = 0, 8 do begin
		for j = 0, 8 do begin
			poss[r, c, j] = 1
		endfor
	endfor
endfor
for i = 0, (n - 1) do begin
	for j = 0, 8 do begin
		if (j NE (gval[i] - 1)) then begin
			poss[grow[i], gcol[i], j] = 0
		endif
	endfor
endfor
poss = eliminator(poss)
if (total(poss) GT 81) then begin
	a = 0L
	b = 0L
	while (a LE 100L) do begin
		sumvals = total(poss, 3)
		possprime = poss
		r = floor(b / 81.0)
		c = (floor(b / 9.0)) MOD 9
		j = b MOD 9
;		print, r
;		print, c
;		print, j
		if ((sumvals[r, c] GE 2) AND (poss[r, c, j] EQ 1)) then begin
			print, "made it into if loop"
			print, r
			print, c
			print, (j + 1)
			for jprime = 0, 8 do begin
				possprime[r, c, jprime] = delta(j, jprime)
			endfor
			possprime = eliminator(possprime)
			if (total(possprime) EQ 0) then begin
				print, "Possibility Eliminated!"
				poss[r, c, j] = 0
				poss = eliminator(poss)
			endif
			a = a + 1L
		endif
		if ((total(poss) EQ 81) OR (b GT 729L)) then begin
			a = a + 10000L
		endif
		b = b + 1L
	endwhile
endif
print, "Solution begins"
for r = 0L, 8L do begin
	print, "beginning of row"
	for c = 0L, 8L do begin
		count = 0L
		p = 0L
		for j = 0, 8 do begin
			p = p + (j + 1) * poss[r, c, j] * (10L^(count))
			count = count + poss[r, c, j]
		endfor
		print, p
	endfor
endfor
end

Code is in IDL, which is similar to Fortran

[Winston]

I could've done that if I knew how to.

[KrazyHorse]

[Jon Miller]

those are somtimes sort of fun to do

i Get bored of them though

JM

[KrazyHorse]

You never have to do one again, then.

Just copy-paste, enter the requisite initial values, compile in IDL and run...

I only found out about these 2 or 3 days ago.

[Whaleboy]

...well done!

[Imran Siddiqui]

Jesus... and I thought I needed a girlfriend

[Starchild]

You've just knocked out the corner stone of modern British cultural fads.

How popular is Soduku in other countries? It's massive in the UK...We've had Soduku gameshows on TV, dozens of puzzle collections released...Even an intereactive DVD game.

[Jaguar]

I know someone who wrote one, too.

Perhaps you could have saved some time by contacting him.

[Imran Siddiqui]

Originally posted by Starchild
How popular is Soduku in other countries? It's massive in the UK...We've had Soduku gameshows on TV, dozens of puzzle collections released...Even an intereactive DVD game.

And in contrast, I had to look up the thing on Wikipedia. Though it seems somewhat familiar after reading up on it.

[Jaguar]

They got popular in 2005 where I'm from. They're now in newspapers, in the same section as crossword puzzles and the like.

[Jonny]

Originally posted by Jaguar
They got popular in 2005 where I'm from. They're now in newspapers, in the same section as crossword puzzles and the like.

QFditto

[Datajack Franit]

2005

Dawn of the Dead Brains

[ixnay]

From what I can tell they've become popular here; both my parents are hooked on the things.

Before christmas, Barnes & Noble had no less than 3 Sudoku displays set up throughout the store with books and calendars of the things.