codeforces C. Diverse Permutation

C. Diverse Permutation

time limit per test

1 second

memory limit per test

256 megabytes

input

standard input

output

standard output

Permutation p is an ordered set of integers
p₁,   p₂,   ...,   p_n, consisting of
n distinct positive integers not larger than
n. We'll denote as
n the length of permutation p₁,   p₂,   ...,   p_n.

Your task is to find such permutation p of length
n, that the group of numbers
|p₁ - p₂|, |p₂ - p₃|, ..., |p_n - 1 - p_n|
has exactly k distinct elements.

Input

The single line of the input contains two space-separated positive integers
n, k (1 ≤ k < n ≤ 10⁵).

Output

Print n integers forming the permutation. If there are multiple answers, print any of them.

Sample test(s)

Input

3 2

Output

1 3 2

Input

3 1

Output

1 2 3

Input

5 2

Output

1 3 2 4 5

Note

By |x| we denote the absolute value of number
x.

求n个数的序列，相邻两个数的绝对值的不同取值有k个 但详细哪k个数不限

#include <iostream>
#include <stdio.h>
#include <string>
#include <cstring>
#include <algorithm>
#include <cmath>
#define N 100009
using namespace std;
int a[N];
int vis[N];

int main()
{
    int n,k;
    while(~scanf("%d%d",&n,&k))
    {
        int t=n;
        int m=1;

        for(int i=1;i<=k;i+=2)
        {
            a[i]=m;
            m++;
        }
        for(int i=2;i<=k;i+=2)
        {
            a[i]=t;
            t--;
        }

        if(k%2==0)
        {
            for(int i=k+1;i<=n;i++)
            a[i]=a[i-1]-1;
        }
        else
        for(int i=k+1;i<=n;i++)
          a[i]=a[i-1]+1;

        for(int i=1;i<n;i++)
        cout<<a[i]<<" ";
        cout<<a[n]<<endl;
    }
    return 0;
}