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.

# @lc code=start
using LeetCode

function beautiful_arrangement(n, k)
    res = [1:(n-k);]
    i = res[end] + 1
    j = n
    while i < j
        push!(res, j)
        j -= 1
        push!(res, i)
        i += 1
    end
    i == j && push!(res, i)
    return res
end
# @lc code=end

beautiful_arrangement (generic function with 1 method)

This page was generated using DemoCards.jl and Literate.jl.