Time: 415 ms (86.33%), Space: 44.5 MB (96.04%) - LeetHub

Author: hogan-tech

0446-arithmetic-slices-ii-subsequence/0446-arithmetic-slices-ii-subsequence.py

@@ -0,0 +1,24 @@
+from collections import defaultdict
+from typing import List
+
+
+class Solution:
+    def numberOfArithmeticSlices(self, nums: List[int]) -> int:
+        n = len(nums)
+        totalCount = 0
+
+        dp = [defaultdict(int) for _ in range(n)]
+
+        for i in range(1, n):
+            for j in range(i):
+                diff = nums[i] - nums[j]
+
+                if diff < -2**31 or diff > 2**31 - 1:
+                    continue
+
+                count = dp[j][diff] if diff in dp[j] else 0
+
+                totalCount += count
+                dp[i][diff] += count + 1
+
+        return totalCount