> For the complete documentation index, see [llms.txt](https://zhongquan789.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://zhongquan789.gitbook.io/leetcode/leetcode/leetcode_910.md).

# leetcode\_910

Given an array A of integers, for each integer A\[i] we need to choose either x = -K or x = K, and add x to A\[i] (only once).

After this process, we have some array B.

Return the smallest possible difference between the maximum value of B and the minimum value of B.

Example 1:

Input: A = \[1], K = 0 Output: 0 Explanation: B = \[1] Example 2:

Input: A = \[0,10], K = 2 Output: 6 Explanation: B = \[2,8] Example 3:

Input: A = \[1,3,6], K = 3 Output: 3 Explanation: B = \[4,6,3]

Note:

1 <= A.length <= 10000 0 <= A\[i] <= 10000 0 <= K <= 10000

## Solutions

1. **greedy O(nlog(n))**
2. reference: <https://leetcode-cn.com/problems/smallest-range-ii/solution/tai-nan-liao-zhi-neng-hua-tu-ping-zhi-jue-by-user8/>
3. Split the sorted array into two parts, then move the lower part `k` steps forward and the other part `k` steps downward. Check reference for demonstration figures.

```cpp
class Solution {
public:
    int smallestRangeII(vector<int>& A, int K) {
        if (A.size() <= 1) return 0;
        sort(A.begin(), A.end());

        int n = A.size(), res = A.back() - A.front();
        for (int i = 0; i < n - 1; i++) {
            int hi = max(A[i] + K, A[n - 1] - K);
            int lo = min(A[0] + K, A[i + 1] - K);
            res = min(res, hi - lo);
        }

        return res;
    }
};
```


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://zhongquan789.gitbook.io/leetcode/leetcode/leetcode_910.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.