Create 740_Delete_and_Earn.md

Author: koji

740_Delete_and_Earn.md

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+## 740. Delete and Earn
+
+
+```
+Given an array nums of integers, you can perform operations on the array.
+
+In each operation, you pick any nums[i] and delete it to earn nums[i] points. After, you must delete every element equal to nums[i] - 1 or nums[i] + 1.
+
+You start with 0 points. Return the maximum number of points you can earn by applying such operations.
+
+ 
+
+Example 1:
+
+Input: nums = [3,4,2]
+Output: 6
+Explanation: Delete 4 to earn 4 points, consequently 3 is also deleted.
+Then, delete 2 to earn 2 points.
+6 total points are earned.
+Example 2:
+
+Input: nums = [2,2,3,3,3,4]
+Output: 9
+Explanation: Delete 3 to earn 3 points, deleting both 2's and the 4.
+Then, delete 3 again to earn 3 points, and 3 again to earn 3 points.
+9 total points are earned.
+ 
+
+Constraints:
+
+1 <= nums.length <= 2 * 104
+1 <= nums[i] <= 104
+```
+
+
+```python
+class Solution:
+ def deleteAndEarn(self, nums: List[int]) -> int:
+ 
+ 
+ # [2,5,5,6,6,4,4,10,10,10]
+ # 1 2. 3. 4. 5. 6. 7. 8. 9 10
+ # [0, 2, 0, 8, 10, 12, 0, 0, 0, 30]
+ # convert array for house rubber
+ 
+ # convert arr for house robber
+ max_val = max(nums)
+ arr = [0] * max_val
+ 
+ for num in nums:
+ arr[num-1] += num
+ 
+ size = len(arr)
+ if size == 1:
+ return arr[0]
+ dp = [0] * (size)
+ dp[0] = arr[0]
+ dp[1] = max(arr[0], arr[1])
+ 
+ for i in range(2, size):
+ dp[i] = max(dp[i-1], dp[i-2] + arr[i])
+ 
+ return dp[-1]
+```
+
+
+```
+Runtime: 56 ms, faster than 69.52% of Python3 online submissions for Delete and Earn.
+Memory Usage: 14.7 MB, less than 28.38% of Python3 online submissions for Delete and Earn.
+```