Create delete_and_earn.py

Author: avidLearnerInProgress

Diff for: delete_and_earn.py

@@ -0,0 +1,35 @@
+class Solution:
+    def deleteAndEarn(self, nums: List[int]) -> int:
+        def solve(nums: List[int], index: int) -> int:
+            nonlocal memoize
+            
+            #base case
+            n = len(nums)
+            if index >= n:
+                return 0
+            
+            #check for memoization
+            if memoize[index] != -1:
+                return memoize[index]
+            
+            #induction
+            
+            currValue = currSum = nums[index]
+            nextIndex = index + 1
+            
+            while nextIndex < n and currValue == nums[nextIndex]: 
+                currSum += nums[nextIndex] #prefix sum for same values
+                nextIndex += 1
+            
+            while nextIndex < n and currValue + 1 == nums[nextIndex]: #skip
+                nextIndex += 1
+                
+            
+            memoize[index] = max(currSum + solve(nums, nextIndex), solve(nums, index + 1)) #pick, unpick
+            
+            return memoize[index]
+        
+        nums.sort()
+        memoize = [-1 for _ in range(200001)] # constraints
+        return solve(nums, 0)
+