Slightly Decreasing Permutations

最新推荐文章于 2016-11-23 23:47:31 发布

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本文介绍了一个算法问题，即如何生成长度为n且下降系数为k的排列。下降系数定义为排列中满足pi > pi+1条件的元素对数量。文章提供了实现这一功能的C++代码示例。

Description

Permutationp is an ordered set of integersp₁, p₂, ..., p_n, consisting ofn distinct positive integers, each of them doesn't exceedn. We'll denote the i-th element of permutation p asp_i. We'll call numbern the size or the length of permutation p₁, p₂, ..., p_n.

The decreasing coefficient of permutation p₁, p₂, ..., p_n is the number of suchi (1 ≤ i < n), that p_i > p_i + 1.

You have numbers n and k. Your task is to print the permutation of length n with decreasing coefficient k.

Input

The single line contains two space-separated integers: n, k (1 ≤ n ≤ 10⁵, 0 ≤ k < n) — the permutation length and the decreasing coefficient.

Output

In a single line print n space-separated integers:p₁, p₂, ..., p_n — the permutation of lengthn with decreasing coefficient k.

If there are several permutations that meet this condition, print any of them. It is guaranteed that the permutation with the sought parameters exists.

Sample Input

Input

5 2

Output

1 5 2 4 3

Input

3 0

Output

1 2 3

Input

3 2

Output

3 2 1

#include<cstdio>
#include<iostream>
using namespace std;

int main(){
    int n,k,i;
    while(cin>>n>>k){
        for(i=0;i<k;i++){
            printf("%d ",n-i);
        }
        for(i=1;i<=n-k;i++){
            printf("%d ",i);
        }
        printf("\n");
    }
    return 0;
}