Task: Sudoku







Python: def initiate():
    box.append([0, 1, 2, 9, 10, 11, 18, 19, 20])
    box.append([3, 4, 5, 12, 13, 14, 21, 22, 23])
    box.append([6, 7, 8, 15, 16, 17, 24, 25, 26])
    box.append([27, 28, 29, 36, 37, 38, 45, 46, 47])
    box.append([30, 31, 32, 39, 40, 41, 48, 49, 50])
    box.append([33, 34, 35, 42, 43, 44, 51, 52, 53])
    box.append([54, 55, 56, 63, 64, 65, 72, 73, 74])
    box.append([57, 58, 59, 66, 67, 68, 75, 76, 77])
    box.append([60, 61, 62, 69, 70, 71, 78, 79, 80])
    for i in range(0, 81, 9):
        row.append(range(i, i+9))
    for i in range(9):
        column.append(range(i, 80+i, 9))

def valid(n, pos):
    current_row = pos/9
    current_col = pos%9
    current_box = (current_row/3)*3 + (current_col/3)
    for i in row[current_row]:
        if (grid[i] == n):
            return False
    for i in column[current_col]:
        if (grid[i] == n):
            return False
    for i in box[current_box]:
        if (grid[i] == n):
            return False
    return True

def solve():
    i = 0
    proceed = 1
    while(i < 81):
        if given[i]:
            if proceed:
                    i += 1
            else:
                i -= 1
        else:
            n = grid[i]
            prev = grid[i]
            while(n < 9):
              if (n < 9):
                  n += 1
              if valid(n, i):
                  grid[i] = n
                  proceed = 1
                  break
            if (grid[i] == prev):
               grid[i] = 0
               proceed = 0
            if proceed:
               i += 1
            else:
               i -=1

def inputs():
    nextt = 'T'
    number = 0
    pos = 0
    while(not(nextt == 'N' or nextt == 'n')):
        print "Enter the position:",
        pos = int(raw_input())
        given[pos - 1] = True
        print "Enter the numerical:",
        number = int(raw_input())
        grid[pos - 1] = number
        print "Do you want to enter another given?(Y, for yes: N, for no)"
        nextt = raw_input()


grid = [0]*81
given = [False]*81
box = []
row = []
column = []
initiate()
inputs()
solve()
for i in range(9):
    print grid[i*9:i*9+9]
raw_input()





Ada: with Ada.Text_IO;

procedure Sudoku is
   type sudoku_ar_t is array ( integer range 0..80 ) of integer range 0..9;
   FINISH_EXCEPTION : exception;

   procedure prettyprint(sudoku_ar: sudoku_ar_t);
   function checkValidity( val : integer; x : integer; y : integer;  sudoku_ar: in  sudoku_ar_t) return Boolean;
   procedure placeNumber(pos: Integer; sudoku_ar: in out sudoku_ar_t);
   procedure solve(sudoku_ar: in out sudoku_ar_t);


   function checkValidity( val : integer; x : integer; y : integer;  sudoku_ar: in  sudoku_ar_t) return Boolean
   is
   begin
      for i in 0..8 loop

         if ( sudoku_ar( y * 9 + i ) = val or sudoku_ar( i * 9 + x ) = val ) then
            return False;
         end if;
      end loop;

      declare
         startX : constant integer := ( x / 3 ) * 3;
         startY : constant integer := ( y / 3 ) * 3;
      begin
         for i in startY..startY+2 loop
            for j in startX..startX+2 loop
               if ( sudoku_ar( i * 9 +j ) = val ) then
                  return False;
               end if;
            end loop;
         end loop;
         return True;
      end;
   end checkValidity;



   procedure placeNumber(pos: Integer; sudoku_ar: in out sudoku_ar_t)
   is
   begin
      if ( pos = 81 ) then
         raise FINISH_EXCEPTION;
      end if;
      if (  sudoku_ar(pos) > 0 ) then
         placeNumber(pos+1, sudoku_ar);
         return;
      end if;
      for n in 1..9 loop
         if( checkValidity( n,  pos mod 9, pos / 9 , sudoku_ar ) ) then
            sudoku_ar(pos) := n;
            placeNumber(pos + 1, sudoku_ar );
            sudoku_ar(pos) := 0;
         end if;
      end loop;
   end placeNumber;


   procedure solve(sudoku_ar: in out sudoku_ar_t)
   is
   begin
      placeNumber( 0, sudoku_ar );
      Ada.Text_IO.Put_Line("Unresolvable !");
   exception
      when FINISH_EXCEPTION =>
         Ada.Text_IO.Put_Line("Finished !");
         prettyprint(sudoku_ar);
   end solve;




   procedure prettyprint(sudoku_ar: sudoku_ar_t)
   is
      line_sep   : constant String  := "
   begin
      for i in sudoku_ar'Range loop
         Ada.Text_IO.Put(sudoku_ar(i)'Image);
         if (i+1) mod 3 = 0 and not((i+1) mod 9 = 0) then
            Ada.Text_IO.Put("|");
         end if;
         if (i+1) mod 9 = 0 then
            Ada.Text_IO.Put_Line("");
         end if;
         if (i+1) mod 27 = 0 then
            Ada.Text_IO.Put_Line(line_sep);
         end if;
      end loop;
   end prettyprint;

   
   sudoku_ar : sudoku_ar_t :=
     (
      8,5,0,0,0,2,4,0,0,
      7,2,0,0,0,0,0,0,9,
      0,0,4,0,0,0,0,0,0,
      0,0,0,1,0,7,0,0,2,
      3,0,5,0,0,0,9,0,0,
      0,4,0,0,0,0,0,0,0,
      0,0,0,0,8,0,0,7,0,
      0,1,7,0,0,0,0,0,0,
      0,0,0,0,3,6,0,4,0
     );

begin
   solve( sudoku_ar );
end Sudoku;