Add gitignore and structure for handling sudoku

Author: RgrMz

.gitignore

@@ -0,0 +1,2 @@
+.vscode/extensions.json
+SudokuSolver/__pycache__/sudoku.cpython-38.pyc

SudokuSolver/examples/ex1.csv

@@ -0,0 +1,10 @@
+a,b,c,d,e,f,g,h,i
+0,1,0,0,5,0,0,0,0
+0,1,0,0,5,0,0,0,0
+0,1,0,0,5,0,0,0,0
+0,1,0,0,5,0,0,0,0
+0,1,0,0,5,0,0,0,0
+0,1,0,0,5,0,0,0,0
+0,1,0,0,5,0,0,0,0
+0,1,0,0,5,0,0,0,0
+0,1,0,0,5,0,0,0,0

SudokuSolver/move.py

@@ -0,0 +1,7 @@
+class Move:
+
+    def __init__(self, number: int, row: int, column: int) -> None:
+
+        self.number = number
+        self.row = row
+        self.column = column

SudokuSolver/read_sudoku.py

@@ -0,0 +1,45 @@
+import numpy as np
+import pandas as pd
+from sudoku import Sudoku
+
+MINIMUM_NUMBERS_FOR_UNIQUE_SOLUTION = 17
+NUMBER_REGIONS = 9
+
+def import_sudoku() -> Sudoku:
+
+    filename = input('Enter the filename\'s path of the sudoku to be solved: ') + '.csv'
+
+    read_sudoku = pd.read_csv(filename).to_numpy()
+
+    sudoku = Sudoku(read_sudoku)
+
+    if is_solvable(sudoku):
+        return sudoku
+
+def is_solvable(sudoku: Sudoku) -> bool:
+
+    # Check there are at least 17 non 0 numbers for unique solution
+
+    if sudoku[sudoku.grid != 0].size < MINIMUM_NUMBERS_FOR_UNIQUE_SOLUTION:
+        return False
+
+    # Check rows' legality
+    for row in sudoku.grid:
+        row = row[row != 0]
+        if np.unique(row).size != row.size:
+            return False
+
+    # Check columns' legality
+    for column in np.nditer(sudoku, flags = ['external_loop'], order='C'):
+        column = column[column != 0]
+        if np.unique(column).size != column.size:
+            return False
+
+    # Check regions' legality
+    for region_number in range(NUMBER_REGIONS):
+        region = getattr(sudoku, 'region'+(region_number+1))
+        region = region[region != 0]
+        if np.unique(region).size != region.size:
+            return False
+
+    return True

SudokuSolver/sudoku.py

@@ -1,11 +1,62 @@
 import numpy as np
+from move import Move
 
 class Sudoku:
 
-    def __init__(self) -> None:
+    def __init__(self, grid: np.ndarray) -> None:
 
-        self.grid = np.zeros((9,9))
+        self.grid = grid
+        self.region1 = self.grid[:3, :3]
+        self.region2 = self.grid[:3, 3:6]
+        self.region3 = self.grid[:3, 6:9]
+        self.region4 = self.grid[3:6, :3]
+        self.region5 = self.grid[3:6, 3:6]
+        self.region6 = self.grid[3:6, 6:9]
+        self.region7 = self.grid[6:9, :3]
+        self.region8 = self.grid[6:9, 3:6]
+        self.region9 = self.grid[6:9, 6:9]
 
-    def put_number(self, number, row, column) -> None:
+    def put_number(self, move: Move) -> None:
 
-        self.grid[row, column] = number
+        self.grid[move.row, move.column] = move.number
+
+    def check_legal_state(self, previous_move: Move) -> bool:
+
+        row_to_check = self.grid[previous_move.row, :].copy()
+        column_to_check = self.grid[:, previous_move.column].copy()
+        region_to_check = self.get_region_from_move(previous_move)
+
+        # Remove 0's from the areas to be checked
+
+        row_to_check = row_to_check[row_to_check != 0]
+        column_to_check = column_to_check[column_to_check != 0]
+        region_to_check = region_to_check[region_to_check != 0]
+
+        # Check if there are repeated numbers after the move
+
+        row_check = np.unique(row_to_check).size == row_to_check.size
+        column_check = np.unique(column_to_check).size == column_to_check.size
+        region_check = np.unique(region_to_check).size == region_to_check.size
+
+        return row_check and column_check and region_check
+
+    def get_region_from_move(self, move: Move) -> np.ndarray :
+
+        if move.row <= 2 and move.column <= 2:
+            return self.region1
+        elif move.row <= 2 and move.column <= 5 and move.column > 2:
+            return self.region2
+        elif move.row <= 2 and move.column <= 9 and move.column > 5:
+            return self.region3
+        elif move.row <= 5 and move.row > 2 and move.column <= 2:
+            return self.region4
+        elif move.row <= 5 and move.row > 2 and move.column <= 5 and move.column > 2:
+            return self.region5
+        elif move.row <= 5 and move.row > 2 and move.column <= 9 and move.column > 5:
+            return self.region6
+        elif move.row <= 9 and move.row > 5 and move.column <= 2:
+            return self.region7
+        elif move.row <= 9 and move.row > 5 and move.column <= 5 and move.column > 2:
+            return self.region8
+        else:
+            return self.region9

SudokuSolver/sudoku_solver.py

@@ -1,3 +1,7 @@
 from sudoku import Sudoku
 
-s = Sudoku()
+LEGIT_NUMBERS = list(range(1,10))
+
+def solve_sudoku(sudoku: Sudoku) -> Sudoku:
+
+    return sudoku