题目
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.
解题思路
贪心，先排序，枚举每个位置，对所有左边的数+k，右边的数-k，求出最大的差值，取最小的为结果
代码
class Solution:
def smallestRangeII(self, A: List[int], K: int) -> int:
A = sorted(set(A))
lo, hi = A[0], A[-1]
res = hi - lo
if res <= K:
return res
if res >= 4 * K:
return res - K * 2
for i in range(len(A) - 1):
a, b = A[i], A[i + 1]
res = min(res, max(hi - K, a + K) - min(lo + K, b - K))
return res
