740. Delete and Earn
描述：

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.

class Solution(object):
    def deleteAndEarn(self, nums):
        points=[0]*1001
        # print(points)
        for num in nums:
            points[num]+=num
        prev,curr=0,0
        for point in points:
            prev,curr=curr,max(point+prev,curr)
        return curr
if __name__=='__main__':
    st=Solution()
    nums = [2, 2, 3, 3, 3, 4,4,4,5,5]
    out=st.deleteAndEarn(nums)
    print(out)