Sudoku: Difference between revisions

include "NSLog.incl"

dim as container gC

short solve_sudoku(short i);

short check_sudoku(short r, short c);

CFMutableStringRef print_sudoku();

short sudoku[9][9] = {

{3,0,0,0,0,1,4,0,9},

{7,0,0,0,0,4,2,0,0},

{0,5,0,2,0,0,0,1,0},

{5,7,0,0,4,3,0,6,0},

{0,9,0,0,0,0,0,3,0},

{0,6,0,7,9,0,0,8,5},

{0,8,0,0,0,5,0,4,0},

{0,0,6,4,0,0,0,0,7},

{9,0,5,6,0,0,0,0,3},

};

short check_sudoku( short r, short c )

{

short i;

short rr, cc;

for (i = 0; i < 9; i++)

if (i != c && sudoku[r][i] == sudoku[r][c]) return 0;

if (i != r && sudoku[i][c] == sudoku[r][c]) return 0;

rr = r/3 * 3 + i/3;

cc = c/3 * 3 + i%3;

if ((rr != r || cc != c) && sudoku[rr][cc] == sudoku[r][c]) return 0;

}

return -1;

}

short solve_sudoku( short i )

{

short r, c;

if (i < 0) return 0;

else if (i >= 81) return -1;

r = i / 9;

c = i % 9;

if (sudoku[r][c])

return check_sudoku(r, c) && solve_sudoku(i + 1);

else

for (sudoku[r][c] = 9; sudoku[r][c] > 0; sudoku[r][c]--)

if ( solve_sudoku(i) ) return -1;

return 0;

}

CFMutableStringRef print_sudoku()

{

short i, j;

CFMutableStringRef mutStr;

mutStr = CFStringCreateMutable( kCFAllocatorDefault, 0 );

for (i = 0; i < 9; i++)

{

for (j = 0; j < 9; j++)

{

CFStringAppendFormat( mutStr, NULL, (CFStringRef)@" %d", sudoku[i][j] );

}

CFStringAppendFormat( mutStr, NULL, (CFStringRef)@"\r" );

}

return( mutStr );

}

dim as short solution

dim as CFMutableStringRef cfRef

gC = " "

cfRef = fn print_sudoku()

fn ContainerCreateWithCFString( cfRef, gC )

print gC

print "No solution found"