<p>You are given an integer array <code>nums</code>. You want to maximize the number of points you get by performing the following operation any number of times:</p>

<ul>
	<li>Pick any <code>nums[i]</code> and delete it to earn <code>nums[i]</code> points. Afterwards, you must delete <b>every</b> element equal to <code>nums[i] - 1</code> and <strong>every</strong> element equal to <code>nums[i] + 1</code>.</li>
</ul>

<p>Return <em>the <strong>maximum number of points</strong> you can earn by applying the above operation some number of times</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> nums = [3,4,2]
<strong>Output:</strong> 6
<strong>Explanation:</strong> You can perform the following operations:
- Delete 4 to earn 4 points. Consequently, 3 is also deleted. nums = [2].
- Delete 2 to earn 2 points. nums = [].
You earn a total of 6 points.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> nums = [2,2,3,3,3,4]
<strong>Output:</strong> 9
<strong>Explanation:</strong> You can perform the following operations:
- Delete a 3 to earn 3 points. All 2&#39;s and 4&#39;s are also deleted. nums = [3,3].
- Delete a 3 again to earn 3 points. nums = [3].
- Delete a 3 once more to earn 3 points. nums = [].
You earn a total of 9 points.</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= nums.length &lt;= 2 * 10<sup>4</sup></code></li>
	<li><code>1 &lt;= nums[i] &lt;= 10<sup>4</sup></code></li>
</ul>

from collections import Counter
"""
[2,2,3,3,3,4,4,5,5,5,6,7,7,8]

score of delete 4 = max score - sumScore(3, 4, 5)
score of delete 4 = deleteEarn(NOT 3 4 5)
deleteEarn(NOT 3 4 5) = total score - sum(3, 4, 5)

score of delete 3. = deleteEarn(NOT 2 3 4)

TAKE curr
 = maxScore [NOT 2, 3] + sum(2)
 don't take curr.
 = maxSore[NOT 2]

"""
class Solution:
    # recursive solution
    def deleteAndEarn(self, nums: List[int]) -> int:
        count = Counter(nums)
        memo = {}

        # returns max number of points you can get up to NUMBER i
        def recurse(i):
            if i <= 0:
                memo[0] = 0
                return 0
            if i not in count:
                if i-1 in memo:
                    memo[i] = memo[i-1]
                else:
                    memo[i] = recurse(i-1)
                return memo[i]
            if i-2 in memo:
                take = count[i] * i + memo[i-2]
            else:
                take = count[i] * i + recurse(i-2)

            if i-1 in memo:
                notake = memo[i-1]
            else:
                notake = recurse(i-1)

            memo[i] = max(take, notake)
            return memo[i]

        return recurse(max(nums))


        
21288