lovejike
diff --git a/‎.DS_Store
4 KB b/‎.DS_Store
4 KB
diff --git a/‎1277.统计全为1的正方形子矩阵/1277-统计全为1的正方形子矩阵.py
Lines changed: 17 additions & 13 deletions b/‎1277.统计全为1的正方形子矩阵/1277-统计全为1的正方形子矩阵.py
Lines changed: 17 additions & 13 deletions
@@ -4,22 +4,26 @@ def countSquares(self, matrix):
         :type matrix: List[List[int]]
         :rtype: int
         """
+        if not matrix or not matrix[0]:
+            return 0
+        
         m, n = len(matrix), len(matrix[0])
-        res = 0
         dp = [[0 for _ in range(n)] for _ in range(m)]
-        for i in range(m):
-            dp[i][0] = matrix[i][0]
-            res += dp[i][0]
-            
-        for j in range(1, n):
-            dp[0][j] = matrix[0][j]
-            res += dp[0][j]
-            
+        
+        res = 0
+        for j in range(n):
+            if matrix[0][j]:
+                res += 1
+                dp[0][j] = 1
+        
+        for i in range(1, m):
+            if matrix[i][0]:
+                res += 1
+                dp[i][0] = 1
+                
         for i in range(1, m):
             for j in range(1, n):
                 if matrix[i][j]:
-                    dp[i][j] = min(dp[i - 1][j], dp[i - 1][j - 1], dp[i][j - 1]) + 1
+                    dp[i][j] = min(dp[i - 1][j - 1], dp[i - 1][j], dp[i][j - 1]) + 1
                     res += dp[i][j]
-        print dp
-        return res
-            
+        return res