2202. Maximize the Topmost Element After K Moves
Description
You are given a 0-indexed integer array nums
representing the contents of a pile, where nums[0]
is the topmost element of the pile.
In one move, you can perform either of the following:
- If the pile is not empty, remove the topmost element of the pile.
- If there are one or more removed elements, add any one of them back onto the pile. This element becomes the new topmost element.
You are also given an integer k
, which denotes the total number of moves to be made.
Return the maximum value of the topmost element of the pile possible after exactly k
moves. In case it is not possible to obtain a non-empty pile after k
moves, return -1
.
Example 1:
Input: nums = [5,2,2,4,0,6], k = 4 Output: 5 Explanation: One of the ways we can end with 5 at the top of the pile after 4 moves is as follows: - Step 1: Remove the topmost element = 5. The pile becomes [2,2,4,0,6]. - Step 2: Remove the topmost element = 2. The pile becomes [2,4,0,6]. - Step 3: Remove the topmost element = 2. The pile becomes [4,0,6]. - Step 4: Add 5 back onto the pile. The pile becomes [5,4,0,6]. Note that this is not the only way to end with 5 at the top of the pile. It can be shown that 5 is the largest answer possible after 4 moves.
Example 2:
Input: nums = [2], k = 1 Output: -1 Explanation: In the first move, our only option is to pop the topmost element of the pile. Since it is not possible to obtain a non-empty pile after one move, we return -1.
Constraints:
1 <= nums.length <= 105
0 <= nums[i], k <= 109
Solutions
Solution 1
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