diff --git a/leetcode/36_valid_sudoku.py b/leetcode/36_valid_sudoku.py
new file mode 100644
index 0000000..8105b5a
--- /dev/null
+++ b/leetcode/36_valid_sudoku.py
@@ -0,0 +1,50 @@
+from typing import List
+import pytest
+
+
+class Solution:
+    def isValidSudoku(self, board: List[List[str]]) -> bool:
+        rows, cols, cubes = set(), set(), set()
+        for i in range(9):
+            for j in range(9):
+                val = board[i][j]
+                if not val.isdigit():
+                    continue
+
+                cube = (i // 3) * 3 + (j // 3)
+                if (i, val) in rows or (j, val) in cols or (cube, val) in cubes:
+                    return False
+
+                rows.add((i, val))
+                cols.add((j, val))
+                cubes.add((cube, val))
+
+        return True
+
+
+@pytest.fixture
+def solution():
+    return Solution()
+
+
+@pytest.mark.parametrize(
+    "sudoku, expected",
+    [
+        (
+            [
+                ["5", "3", ".", ".", "7", ".", ".", ".", "."],
+                ["6", ".", ".", "1", "9", "5", ".", ".", "."],
+                [".", "9", "8", ".", ".", ".", ".", "6", "."],
+                ["8", ".", ".", ".", "6", ".", ".", ".", "3"],
+                ["4", ".", ".", "8", ".", "3", ".", ".", "1"],
+                ["7", ".", ".", ".", "2", ".", ".", ".", "6"],
+                [".", "6", ".", ".", ".", ".", "2", "8", "."],
+                [".", ".", ".", "4", "1", "9", ".", ".", "5"],
+                [".", ".", ".", ".", "8", ".", ".", "7", "9"],
+            ],
+            True,
+        )
+    ],
+)
+def test_search(solution: Solution, sudoku: List[List[str]], expected: bool):
+    assert solution.isValidSudoku(sudoku) == expected