题目
Given two integers n and k, construct a list answer that contains n different positive integers ranging from 1 to n and obeys the following requirement:
Suppose this list is answer = [a1, a2, a3, … , an], then the list [|a1 - a2|, |a2 - a3|, |a3 - a4|, … , |an-1 - an|] has exactly k distinct integers. Return the list answer. If there multiple valid answers, return any of them.
解题思路
直接进行构造，先把1到n-k放到结果里，之后每个数相差从k到1
代码
class Solution:
def constructArray(self, n: int, k: int) -> List[int]:
res = list(range(1, n - k + 1))
f, d = 1, k
for i in range(k):
res.append(res[-1] + f * d)
f = -f
d -= 1
return res
