You are given a?0-indexed?integer array?nums?and an integer?k. Your task is to perform the following operation?exactly?k?times in order to maximize your score:

1. Select an element?m?from?nums.

2. Remove the selected element?m?from the array.

3. Add a new element with a value of?m + 1?to the array.

4. Increase your score by?m.

Return?the maximum score you can achieve after performing the operation exactly?k?times.

?

Example 1:

Input: nums = [1,2,3,4,5], k = 3

Output: 18

Explanation:?

We need to choose exactly 3 elements from nums to maximize the sum.?

For the first iteration, we choose 5. Then sum is 5 and nums = [1,2,3,4,6]?

For the second iteration, we choose 6. Then sum is 5 + 6 and nums = [1,2,3,4,7]?

For the third iteration, we choose 7. Then sum is 5 + 6 + 7 = 18 and nums = [1,2,3,4,8]?

So, we will return 18. It can be proven,?

that 18 is the maximum answer that we can achieve.

Example 2:

Input: nums = [5,5,5], k = 2

Output: 11

Explanation: We need to choose exactly 2 elements from nums to maximize the sum.?

For the first iteration, we choose 5. Then sum is 5 and nums = [5,5,6]?

For the second iteration, we choose 6. Then sum is 5 + 6 = 11 and nums = [5,5,7]

So, we will return 11.?

It can be proven, that 11 is the maximum answer that we can achieve.

?

Constraints:

• 1 <= nums.length <= 100

• 1 <= nums[i] <= 100

• 1 <= k <= 100

?easy題目，不多解釋，就是先找到最大值，然后根據(jù)等差數(shù)列求和的公式計算出結(jié)果，

返回即可；

Runtime:?7 ms, faster than?56.91%?of?Java?online submissions for?Maximum Sum With Exactly K Elements?.

Memory Usage:?42.5 MB, less than?92.06%?of?Java?online submissions for?Maximum Sum With Exactly K Elements?.