Diverse Permutation - CodeForces 482 A 水题

A. 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 asn 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.

题意：排列n个数，使得相邻两个数的差一共有k种。

思路：我们不难想出最多有n-1种差，假设n是10的话，那么就是1、10、2、9、3、8、4、7、5、6这么排，减少k的话，只需要让后面的按顺序使得差为1即可。

AC代码如下：

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<cmath>
using namespace std;
typedef long long ll;
int main()
{
    int T,t,n,m,i,j,k,l,r;
    scanf("%d%d",&n,&k);
    l=1;r=n;
    for(i=1;i<=k;i++)
    {
        if(i&1)
        {
            printf("%d ",l);
            l++;
        }
        else
        {
            printf("%d ",r);
            r--;
        }
    }
    if(!(i&1))
    for(i=l;i<=r;i++)
       printf("%d ",i);
    else
    for(i=r;i>=l;i--)
       printf("%d ",i);
    printf("\n");
}