输出1~n的按字典序从小到大的顺序数第m个排列

#include <iostream>

using namespace std;

const int N = 110;

int n, m;
int path[N];
bool st[N];

bool dfs(int u)
{
    if (u == n)
    {
        m--;
        if (!m)
        {
            for (int i = 0; i < n; i++)
                cout << path[i] << " ";
            cout << endl;
            return true;
        }
        return false;
    }

    for (int i = 1; i <= n; i++)
    {
        if (!st[i])
        {
            path[u] = i;
            st[i] = true;

            if (dfs(u + 1))
                return true;

            st[i] = false;
        }
    }

    return false;
}

int main()
{
    cin >> n >> m;
    dfs(0);
    return 0;
}