update 37

leetcode/37.py

@@ -0,0 +1,37 @@
+# Sudoku Solver
+
+
+class Solution:
+    def solveSudoku(self, board: list[list[int]]) -> None:
+        def isValid(board, row, col, num):
+            # Check if the number is in the current row
+            for x in range(9):
+                if board[row][x] == num:
+                    return False
+                if board[x][col] == num:
+                    return False
+
+            startRow, startCol = 3 * (row // 3), 3 * (col // 3)
+            for i in range(3):
+                for j in range(3):
+                    if board[startRow + i][startCol + j] == num:
+                        return False
+
+            return True
+
+        def solve(board):
+            for i in range(9):
+                for j in range(9):
+                    if broad[i][j] == ".":
+                        # Try all numbers for empty cell
+                        for num in map(str, range(1, 10)):
+                            if isValid(board, i, j, num):
+                                board[i][j] = num
+                                if solve(board):
+                                    return True
+                                board[i][j] = "."
+
+                        return False
+            return False
+
+        solve(board)