Time: 214 ms (48.34%) | Memory: 37.8 MB (33.90%) - LeetSync

Author: jagrit007

494-target-sum/target-sum.py

@@ -0,0 +1,16 @@
+class Solution:
+    def findTargetSumWays(self, nums: List[int], target: int) -> int:
+        dp = {}
+        def helper(ind, sum):
+            if ind == len(nums):
+                return 1 if sum == target else 0
+            if (ind, sum) in dp:
+                return dp[(ind, sum)]
+
+            dp[(ind, sum)] = (helper(ind+1, sum + nums[ind]) +
+                              helper(ind+1, sum - nums[ind]))
+            return dp[(ind, sum)]
+        return helper(0, 0)
+            
+
+