Data commit

Task/Sudoku/Crystal/sudoku.crystal

@@ -0,0 +1,73 @@
+GRID_SIZE = 9
+
+def isNumberInRow(board, number, row)
+  board[row].includes?(number)
+end
+def isNumberInColumn(board, number, column)
+  board.any?{|row| row[column] == number }
+end
+def isNumberInBox(board, number, row, column)
+  localBoxRow = row - row % 3
+  localBoxColumn = column - column % 3
+  (localBoxRow...(localBoxRow+3)).each do |i|
+    (localBoxColumn...(localBoxColumn+3)).each do |j|
+      return true if board[i][j] == number
+    end
+  end
+  false
+end
+
+def isValidPlacement(board, number, row, column)
+  return !isNumberInRow(board, number, row) &&
+  !isNumberInColumn(board, number, column) &&
+  !isNumberInBox(board, number, row, column)
+end
+
+def solveBoard(board)
+  board.each_with_index do |row, i|
+    row.each_with_index do |cell, j|
+      if(cell == 0)
+        (1..GRID_SIZE).each do |n|
+          if(isValidPlacement(board,n,i,j))
+            board[i][j]=n
+            if(solveBoard(board))
+              return true
+            else
+              board[i][j]=0
+            end
+          end
+        end
+        return false
+      end
+    end
+  end
+  return true
+end
+
+def printBoard(board)
+  board.each_with_index do |row, i|
+    row.each_with_index do |cell, j|
+      print cell
+      print '|' if j == 2 || j == 5
+      print '\n' if j == 8
+    end
+    print "-"*11 + '\n' if i == 2 || i == 5
+  end
+  print '\n'
+end
+
+board = [
+  [7, 0, 2, 0, 5, 0, 6, 0, 0],
+  [0, 0, 0, 0, 0, 3, 0, 0, 0],
+  [1, 0, 0, 0, 0, 9, 5, 0, 0],
+  [8, 0, 0, 0, 0, 0, 0, 9, 0],
+  [0, 4, 3, 0, 0, 0, 7, 5, 0],
+  [0, 9, 0, 0, 0, 0, 0, 0, 8],
+  [0, 0, 9, 7, 0, 0, 0, 0, 5],
+  [0, 0, 0, 2, 0, 0, 0, 0, 0],
+  [0, 0, 7, 0, 4, 0, 2, 0, 3]]
+
+printBoard(board)
+if(solveBoard(board))
+  printBoard(board)
+end