Create check-if-there-is-a-valid-partition-for-the-array.py

Author: kamyu104

Python/check-if-there-is-a-valid-partition-for-the-array.py

@@ -0,0 +1,20 @@
+# Time:  O(n)
+# Space: O(1)
+
+# dp
+class Solution(object):
+    def validPartition(self, nums):
+        """
+        :type nums: List[int]
+        :rtype: bool
+        """
+        dp = [False]*4
+        dp[0] = True
+        for i in xrange(len(nums)):
+            dp[(i+1)%4] = False
+            if i-1 >= 0 and nums[i] == nums[i-1]:
+                dp[(i+1)%4] |= dp[((i+1)-2)%4]
+            if i-2 >= 0 and (nums[i] == nums[i-1] == nums[i-2] or
+                             nums[i] == nums[i-1]+1 == nums[i-2]+2):
+                dp[(i+1)%4] |= dp[((i+1)-3)%4]
+        return dp[len(nums)%4]