sudoku_solver.py

sudoku.py

@@ -0,0 +1,59 @@
+M = 9
+def puzzle(a):
+    for i in range(M):
+        for j in range(M):
+            print(a[i][j],end = " ")
+        print()
+def solve(grid, row, col, num):
+    for x in range(9):
+        if grid[row][x] == num:
+            return False
+
+    for x in range(9):
+        if grid[x][col] == num:
+            return False
+
+
+    startRow = row - row % 3
+    startCol = col - col % 3
+    for i in range(3):
+        for j in range(3):
+            if grid[i + startRow][j + startCol] == num:
+                return False
+    return True
+
+def Suduko(grid, row, col):
+
+    if (row == M - 1 and col == M):
+        return True
+    if col == M:
+        row += 1
+        col = 0
+    if grid[row][col] > 0:
+        return Suduko(grid, row, col + 1)
+    for num in range(1, M + 1, 1): 
+
+        if solve(grid, row, col, num):
+
+            grid[row][col] = num
+            if Suduko(grid, row, col + 1):
+                return True
+        grid[row][col] = 0
+    return False
+
+'''0 means the cells where no value is assigned'''
+grid = [
+    [0, 5, 0, 0, 0, 0, 0, 0, 7],
+    [6, 9, 4, 0, 0, 7, 8, 0, 0],
+    [0, 7, 3, 0, 0, 6, 1, 0, 9],
+    [0, 1, 0, 0, 0, 0, 0, 3, 0],
+    [3, 6, 9, 0, 0, 0, 0, 0, 1],
+    [5, 0, 0, 9, 1, 0, 0, 0, 0],
+    [0, 3, 0, 0, 6, 0, 4, 1, 0],
+    [0, 4, 0, 3, 0, 0, 7, 0, 0],
+    [7, 2, 0, 0, 0, 5, 0, 0, 0]]
+
+if (Suduko(grid, 0, 0)):
+    puzzle(grid)
+else:
+    print("Solution does not exist:(")