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,   ...,   pn, consisting of n distinct positive integers not larger than n. We'll denote as n the length of permutation p1,   p2,   ...,   pn.

Your task is to find such permutation p of length n, that the group of numbers |p1 - p2|, |p2 - p3|, ..., |pn - 1 - pn| 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;
}



posted @ 2017-08-04 08:06  yxysuanfa  阅读(205)  评论(0编辑  收藏  举报