Permutations

B1. Permutations

time limit per test

2 seconds

memory limit per test

256 megabytes

input

standard input

output

standard output

You are given a permutation p of numbers 1, 2, ..., n. Let's define f(p) as the following sum:

Find the lexicographically m-th permutation of length n in the set of permutations having the maximum possible value of f(p).

Input

The single line of input contains two integers n and m (1 ≤ m ≤ cnt_n), where cnt_n is the number of permutations of length n with maximum possible value of f(p).

The problem consists of two subproblems. The subproblems have different constraints on the input. You will get some score for the correct submission of the subproblem. The description of the subproblems follows.

• In subproblem B1 (3 points), the constraint 1 ≤ n ≤ 8 will hold.
• In subproblem B2 (4 points), the constraint 1 ≤ n ≤ 50 will hold.

Output

Output n number forming the required permutation.

Sample test(s)

Input

2 2

Output

2 1 

Input

3 2

Output

1 3 2 

Note

In the first example, both permutations of numbers {1, 2} yield maximum possible f(p) which is equal to 4. Among them, (2, 1) comes second in lexicographical order.

B1:   1<=n<=8;

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <stack>
#include <queue>
using namespace std;
const int INF = 0x7fffffff;
const int MS = 100005;
const double EXP = 1e-8;
int a[55];
int n, m;
int calc()
{
    int res = 0;
    for (int i = 0; i < n; i++)
        for (int j = i; j < n; j++)
        {
            int maxv = n;
            for (int k = i; k <= j; k++)
                if (maxv>a[k])
                    maxv = a[k];
            res += maxv;
        }
    return res;
}
void solve()
{
    int i, j;
    for (i = 0; i < n; i++)
        a[i] = i + 1;
    int maxv = -INF;
    do
    {
        int s = calc();
        if (maxv < s)
            maxv = s;
    } while (next_permutation(a, a + n));

    sort(a, a + n);
    do
    {
        int s = calc();
        if (maxv == s)
        {
            m--;
            if (!m)
            {
                for (i = 0; i < n; i++)
                {
                    if (i)
                        cout << " ";
                    cout << a[i];
                }
                break;
            }
        }

    } while (next_permutation(a, a + n));
    return;
}

int main()
{
    cin >> n >> m;
    solve();
    //void print(int, int *, int);
    //print(n, a, 0);
    return 0;
}
/*
void print(int n, int *a, int cur)
{
    if (cur == n)
    {
        //print
        for (int i = 0; i < n; i++)
        {
            if (i)
                cout << " ";
            cout << a[i];
        }
        cout << endl;
    }
    else
    {
        for (int i = 1; i <= n; i++)
        {
            int ok = 1;
            for (int j = 0; j < cur&&ok; j++)
            {
                if (a[j] == i)
                    ok = 0;
            }
            if (ok)
            {
                a[cur] = i;
                print(n, a, cur + 1);
            }
        }
    }
    return;
}

*/

B2:1<=n<=50;

#include <iostream>
using namespace std;
long long m, n, ans[50];

int main() 
{
    cin >> n >> m;
    int l = 0, r = n - 1;
    for(int i = 1; i <= n; i++) 
    {
        if(i == n)
        {
            if((m - 1) & ((1ll << n) - 1)) 
                ans[r--] = i;
            else 
                ans[l++] = i;
        }
        else
        { 
            if((m - 1) & (1ll << (n - i - 1))) 
                ans[r--] = i;
            else 
                ans[l++] = i;
        }
    }
    for(int i = 0; i < n; i++) 
        cout << ans[i] << ' ';
    cout << endl;
}