validator.py

#from Geeks for Geeks lol

def isinRange(board):
   
  N = 9
   
  # Traverse board[][] array
  for i in range(0, N):
    for j in range(0, N):
       
      # Check if board[i][j]
      # lies in the range
      if ((board[i][j] <= 0) or
          (board[i][j] > 9)):
        return False
       
  return True
 
# Function to check if the solution
# of sudoku puzzle is valid or not
def isValidSudoku(board):
   
  N = 9
   
  # Check if all elements of board[][]
  # stores value in the range[1, 9]
  if (isinRange(board) == False):
    return False
 
  # Stores unique value
  # from 1 to N
  unique = [False] * (N + 1)
 
  # Traverse each row of
  # the given array
  for i in range(0, N):
     
    # Initialize unique[]
    # array to false
    for m in range(0, N + 1):
      unique[m] = False
 
    # Traverse each column
    # of current row
    for j in range(0, N):
       
      # Stores the value
      # of board[i][j]
      Z = board[i][j]
 
      # Check if current row
      # stores duplicate value
      if (unique[Z] == True):
        return False
       
      unique[Z] = True
 
  # Traverse each column of
  # the given array
  for i in range(0, N):
     
    # Initialize unique[]
    # array to false
    for m in range(0, N + 1):
      unique[m] = False
 
    # Traverse each row
    # of current column
    for j in range(0, N):
       
      # Stores the value
      # of board[j][i]
      Z = board[j][i]
 
      # Check if current column
      # stores duplicate value
      if (unique[Z] == True):
        return False
       
      unique[Z] = True
 
  # Traverse each block of
  # size 3 * 3 in board[][] array
  for i in range(0, N - 2, 3):
     
    # j stores first column of
    # each 3 * 3 block
    for j in range(0, N - 2, 3):
       
      # Initialize unique[]
      # array to false
      for m in range(0, N + 1):
        unique[m] = False
 
      # Traverse current block
      for k in range(0, 3):
        for l in range(0, 3):
           
          # Stores row number
          # of current block
          X = i + k
 
          # Stores column number
          # of current block
          Y = j + l
 
          # Stores the value
          # of board[X][Y]
          Z = board[X][Y]
 
          # Check if current block
          # stores duplicate value
          if (unique[Z] == True):
            return False
           
          unique[Z] = True
           
  # If all conditions satisfied
  return True