HDU5916

Harmonic Value Description

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 287    Accepted Submission(s): 184
Special Judge

Problem Description

The harmonic value of the permutation p1,p2,⋯pn is

∑i=1n−1gcd(pi.pi+1)

Mr. Frog is wondering about the permutation whose harmonic value is the strictly k-th smallest among all the permutations of [n].

 

 

Input

The first line contains only one integer T (1≤T≤100), which indicates the number of test cases.

For each test case, there is only one line describing the given integers n and k (1≤2k≤n≤10000).

 

 

Output

For each test case, output one line “Case #x: p1 p2 ⋯ pn”, where x is the case number (starting from 1) and p1 p2 ⋯ pn is the answer.

 

 

Sample Input

2

4 1

4 2

 

 

Sample Output

Case #1: 4 1 3 2

Case #2: 2 4 1 3

 

 

Source

2016中国大学生程序设计竞赛（长春）-重现赛

 

求gcd值第k小的1到n的排列。

//2016.10.08
#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

int main()
{
    int T, n, k, kase = 0;
    scanf("%d", &T);
    while(T--)
    {
        int tmp = -1;
        scanf("%d%d", &n, &k);
        printf("Case #%d:", ++kase);
        if(k == 1){
            for(int i = 1; i <= n; i++)
                  printf(" %d", i);
        }else{
            if(k&1){
                printf(" %d %d", 2*k, k);
                for(int i = 2; i <= n; i++)
                {
                    if(i == 2*k)continue;
                    if(i == k)printf(" 1");
                    else printf(" %d", i);
                }
            }else{
                printf(" %d %d", 2*k, k);
                for(int i = 1; i <= n; i++)
                {
                    if(i == k || i == 2*k)continue;
                    else printf(" %d", i);
                }
            }
        }
        printf("\n");
    }

    return 0;
}