Create find-the-k-beauty-of-a-number.py

Author: kamyu104

Python/find-the-k-beauty-of-a-number.py

@@ -0,0 +1,21 @@
+# Time:  O(logn)
+# Space: O(logn)
+
+# sliding window
+class Solution(object):
+    def divisorSubstrings(self, num, k):
+        """
+        :type num: int
+        :type k: int
+        :rtype: int
+        """
+        result = curr = 0
+        s = map(int, str(num))
+        base = 10**(k-1)
+        for i, x in enumerate(s):
+            if i-k >= 0:
+                curr -= s[i-k]*base
+            curr = curr*10+x
+            if i+1 >= k:
+                result += int(curr and num%curr == 0)
+        return result