poj3187

简单题

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>
#include <algorithm>
using namespace std;

#define maxn 15

int n, f[maxn], g[maxn], sum;

int cal()
{
    int ret = 0;
    for (int i = 0; i < n; i++)
        ret += f[i] * g[i];
    return ret;
}

int main()
{
    //freopen("t.txt", "r", stdin);
    scanf("%d%d", &n, &sum);
    memset(f, 0, sizeof(f));
    f[0] = 1;
    for (int i = 1; i < n; i++)
    {
        for (int j = i; j >= 1; j--)
            f[j] = f[j] + f[j - 1];
    }
    for (int i = 0; i < n; i++)
        g[i] = i + 1;
    while (sum != cal())
        next_permutation(g, g + n);
    printf("%d", g[0]);
    for (int i = 1; i < n; i++)
        printf(" %d", g[i]);
    putchar('\n');
    return 0;
}