Create count-partitions-with-even-sum-difference.py

Author: kamyu104

Python/count-partitions-with-even-sum-difference.py

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+# Time:  O(n)
+# Space: O(1)
+
+# prefix sum
+class Solution(object):
+    def countPartitions(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: int
+        """
+        result = left = 0
+        right = sum(nums)
+        for i in xrange(len(nums)-1):
+            left += nums[i]
+            right -= nums[i]
+            if left%2 == right%2:
+                result += 1
+        return result