Create count-square-submatrices-with-all-ones.py

Author: kamyu104

Python/count-square-submatrices-with-all-ones.py

@@ -0,0 +1,16 @@
+# Time:  O(m * n)
+# Space: O(1)
+
+class Solution(object):
+    def countSquares(self, matrix):
+        """
+        :type matrix: List[List[int]]
+        :rtype: int
+        """
+        for i in xrange(1, len(matrix)):
+            for j in xrange(1, len(matrix[0])):
+                if not matrix[i][j]:
+                    continue
+                l = min(matrix[i-1][j], matrix[i][j-1])
+                matrix[i][j] = l+1 if matrix[i-l][j-l] else l
+        return sum(x for row in matrix for x in row)