667. Beautiful Arrangement II

Given two integers `n` and `k`, you need to construct a list which contains `n` different positive integers ranging from `1` to `n` and obeys the following requirement:
Suppose this list is [a1, a2, a3, … , an], then the list [|a1 – a2|, |a2 – a3|, |a3 – a4|, … , |an-1 – an|] has exactly `k` distinct integers.

If there are multiple answers, print any of them.

Example 1:

```Input: n = 3, k = 1
Output: [1, 2, 3]
Explanation: The [1, 2, 3] has three different positive integers ranging from 1 to 3, and the [1, 1] has exactly 1 distinct integer: 1.
```

Example 2:

```Input: n = 3, k = 2
Output: [1, 3, 2]
Explanation: The [1, 3, 2] has three different positive integers ranging from 1 to 3, and the [2, 1] has exactly 2 distinct integers: 1 and 2.
```

Note:

1. The `n` and `k` are in the range 1 <= k < n <= 104.
```class Solution(object):
def constructArray(self, n, k):
"""
:type n: int
:type k: int
:rtype: List[int]
"""
def construct(k):

nums = set(range(2,k+2))
ans = [1]

for d in range(k,0,-1):
if ans[-1] + d in nums:
nums.remove(ans[-1] + d)
ans.append(ans[-1] + d)
else:
nums.remove(ans[-1] - d)
ans.append(ans[-1] - d)

return ans

return construct(k) + range(k+2,n+1)```