Codeforces 482A. Diverse Permutation

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.

找规律咯

  按照     ...3 k-1 2 k 1 k+1 k+2 ... n

  的排法

#include<iostream>
#include<cstring>
#include<cstdio>
#include <string>
#include <sstream>
#include <map>
#include <cmath>
#include <algorithm>
#include <iomanip>
#include <stack>
#include <queue>
#include <set>
using namespace std;
typedef long long LL;
#define MOD 1000000007
int n,k;
int a[100005];
int main(){
  // freopen("test.in","r",stdin);
  cin >> n >> k;
  int now = 1,nowk = k,dist = k,direct = 1,total(0);
  while (dist >= 1){
    if (direct == 1){
      total ++;
      a[total] = now; now ++;
    }
    else {
      total ++;
      a[total] = nowk; nowk --;
    }
    direct = 1 - direct;
    dist --;
  }
  for (int i=total;i>=1;i--){
    cout << a[i] << " ";
  }
  for (int i=k+1;i<=n;i++){
    cout << i << " ";
  }
  return 0;
}