Create number-of-laser-beams-in-a-bank.py

Author: kamyu104

Python/number-of-laser-beams-in-a-bank.py

@@ -0,0 +1,17 @@
+# Time:  O(m * n)
+# Space: O(1)
+
+class Solution(object):
+    def numberOfBeams(self, bank):
+        """
+        :type bank: List[str]
+        :rtype: int
+        """
+        result = prev = 0
+        for x in bank:
+            cnt = x.count('1')
+            if not cnt:
+                continue
+            result += prev*cnt
+            prev = cnt
+        return result