力扣：667. 优美的排列 II

class Solution {
    public int[] constructArray(int n, int k) {
        int[] res = new int[n];
        int idx = 0;
        for (int i = 1; i < n - k; i++) res[idx++] = i;
        for (int i = n - k, j = n; i <= j; i++, j--){
            res[idx++] = i;
            if (i != j) res[idx++] = j;
        }
        return res;
    }
}