Delete and Earn
Difficulty: Medium
Category: DSA
Topics: Array, Hash Table, Dynamic Programming
Asked at: Goldman Sachs
You are given an integer array `nums`. You want to maximize the number of points you get by performing the following operation any number of times:
- Pick any `nums[i]` and delete it to earn `nums[i]` points. Afterwards, you must delete every element equal to `nums[i] - 1` and **every** element equal to `nums[i] + 1`.
Return _the **maximum number of points** you can earn by applying the above operation some number of times_.
**Example 1:**
**Input:** nums = [3,4,2]
**Output:** 6
**Explanation:** 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.
```
**Example 2:**
**Input:** nums = [2,2,3,3,3,4]
**Output:** 9
**Explanation:** You can perform the following operations:
- Delete a 3 to earn 3 points. All 2's and 4'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.
```
**Constraints:**
- `1 <= nums.length <= 2 * 104`
- `1 <= nums[i] <= 104`