13 Ксюше

// 1
#include <iostream>
#include <cmath>
#include <vector>

using namespace std;


int factorial(int n)
{
    return (n == 1 || n == 0) ? 1 : factorial(n - 1) * n;
}

int main() {
    int n, k;
    cin >> n >> k;
    vector<bool> used(n + 1);
    vector<int> answer(n);

    for (int i = 0; i < n; i++) {
        int c = (k - 1) / factorial(n - i - 1) + 1;
        int j = 1;
        int p = 0;

        for (; j <= n; j++) {
            if (!used[j]) {
                p++;
            }
            if (c == p) {
                break;
            }
        }
        k = (k - 1) % factorial(n - i - 1) + 1;
        used[j] = true;
        answer[i] = j;
    }
    for (int i = 0; i < n; i++) {
        cout << answer[i] << " ";
    }
}

// 2

#include <iostream>
#include <vector>

using namespace std;


vector<int> answer;
int n, k;
int cnt = 0;


void comb(int i = 0) {
    if (k - cnt == 0) {
        for (int j = 0; j < k; j++) {
            cout << answer[j] << " ";
        }
        cout << endl;
        return;
    }
    for (; i <= n - k + cnt; i++) {
        answer.push_back(i + 1);
        cnt++;
        comb(i + 1);
        cnt--;
        answer.pop_back();
    }
}

int main() {
    cin >> n >> k;

    comb();

    return 0;
}

// 3

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

int foo(int n, int m) {
    int answer = 1;
    for (int i = n; i > n - m; i--) {
        answer = answer * i;
    }
    return answer;
}


int main() {
    int n, k, m, p = 0;
    cin >> n >> k >> m;
    vector<int> ans(k);
    vector<bool> used(n);

    m--;
    int a = n - 1, b = k - 1;
    for (int i = 0; i < k; i++) {
        p = 0;
        int tmp = foo(a, b);
        int c = m / tmp;
        m -= c * tmp;
        c++;
        while (c != 0) {
            if (!used[p]) {
                c--;
            }
            p++;
        }
        ans[i] = p;
        used[p - 1] = true;
        a--;
        b--;
    }

    for (int j = 0; j < k; j++) {
        cout << ans[j] << " ";
    }
    return 0;
}