Create count-subarrays-with-score-less-than-k.py

Author: kamyu104

Python/count-subarrays-with-score-less-than-k.py

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+# Time:  O(n)
+# Space: O(1)
+
+# sliding window, two pointers
+class Solution(object):
+    def countSubarrays(self, nums, k):
+        """
+        :type nums: List[int]
+        :type k: int
+        :rtype: int
+        """
+        result = total = left = 0
+        for right in xrange(len(nums)):
+            total += nums[right]
+            while total*(right-left+1) >= k:
+                total -= nums[left]
+                left += 1
+            result += right-left+1
+        return result