Total Runtime: 161 ms

michaelhuang · michaelhuang · commit ee2d1deadf98 · 2015-08-06T22:50:30.000+08:00
http://www.lintcode.com/en/problem/valid-sudoku/
diff --git a/Valid_Sudoku.py b/Valid_Sudoku.py
@@ -0,0 +1,22 @@
+class Solution:
+    # @param board, a 9x9 2D array
+    # @return a boolean
+    def isValidSudoku(self, board):
+        # check rows
+        for i in xrange(9):
+            if board[i].count('.') + len(set(board[i])) - 1 != 9:
+                return False
+        # check columns
+        for i in xrange(9):
+            col = [board[j][i] for j in xrange(9)]
+            if col.count('.') + len(set(col)) - 1 != 9:
+                return False
+        # check 3x3 squares
+        for i in (0, 3, 6):
+            for j in (0, 3, 6):
+                square = [board[i + m][j + n]
+                          for m in (0, 1, 2)
+                          for n in (0, 1, 2)]
+                if square.count('.') + len(set(square)) - 1 != 9:
+                    return False
+        return True
