Sudoku: Difference between revisions

funcproc init . .

for pos = 1 to 81

if pos mod 9 = 1

s$ = input

if s$ = ""

s$ = input

lendig = number inp[](pos 0- 1) mod 9 + 1]

forif idig => 1 to len s$0

if substrgrid[pos] s$= i 1 <> " "dig

r inp[] &= number(pos substr- s$1) idiv 19

. c = (pos - 1) mod 9

.

funcproc display . .

for i = 1 to 81

write grid[i] & " "

if i mod 3 = 0

write " "

.

if i mod 9 = 0

print ""

.

if i mod 27 = 0

print ""

.

.

funcproc solve pos . .

while grid[pos] <> 0

pos += 1

.

if pos > 81

# solved

call display

break 1

.

r = (pos - 1) div 9

c = (pos - 1) mod 9

b = r div 3 * 3 + c div 3

r *= 10

c *= 10

b *= 10

for d = 1 to 9

if row[r + d] = 0 and col[c + d] = 0 and box[b + d] = 0

grid[pos] = d

row[r + d] = 1

col[c + d] = 1

box[b + d] = 1

call solve pos + 1

row[r + d] = 0

col[c + d] = 0

box[b + d] = 0

.

.

grid[pos] = 0