[NYIST32]组合数（状压，枚举，暴力）

题目链接：http://acm.nyist.edu.cn/JudgeOnline/problem.php?pid=32

求n个数中挑出r个数字的所有情况，最后倒序输出所有情况。

状压枚举所有情况就是了，判断长度是否符合条件。

/*
━━━━━┒ギリギリ♂ eye！
┓┏┓┏┓┃キリキリ♂ mind！
┛┗┛┗┛┃＼○／
┓┏┓┏┓┃ /
┛┗┛┗┛┃ノ)
┓┏┓┏┓┃
┛┗┛┗┛┃
┓┏┓┏┓┃
┛┗┛┗┛┃
┓┏┓┏┓┃
┛┗┛┗┛┃
┓┏┓┏┓┃
┃┃┃┃┃┃
┻┻┻┻┻┻
*/
#include <algorithm>
#include <iostream>
#include <iomanip>
#include <cstring>
#include <climits>
#include <complex>
#include <fstream>
#include <cassert>
#include <cstdio>
#include <bitset>
#include <vector>
#include <deque>
#include <queue>
#include <stack>
#include <ctime>
#include <set>
#include <map>
#include <cmath>
using namespace std;
#define fr first
#define sc second
#define cl clear
#define BUG puts("here!!!")
#define W(a) while(a--)
#define pb(a) push_back(a)
#define Rint(a) scanf("%d", &a)
#define Rll(a) scanf("%I64d", &a)
#define Rs(a) scanf("%s", a)
#define Cin(a) cin >> a
#define FRead() freopen("in", "r", stdin)
#define FWrite() freopen("out", "w", stdout)
#define Rep(i, len) for(LL i = 0; i < (len); i++)
#define For(i, a, len) for(LL i = (a); i < (len); i++)
#define Cls(a) memset((a), 0, sizeof(a))
#define Clr(a, x) memset((a), (x), sizeof(a))
#define Fuint(a) memset((a), 0x7f7f, sizeof(a))
#define lrt rt << 1
#define rrt rt << 1 | 1
#define pi 3.14159265359
#define RT return
#define lowbit(x) x & (-x)
#define onenum(x) __builtin_popcount(x)
typedef long long LL;
typedef long double LD;
typedef unsigned long long Uint;
typedef pair<LL, LL> pii;
typedef pair<string, LL> psi;
typedef map<string, LL> msi;
typedef vector<LL> vi;
typedef vector<LL> vl;
typedef vector<vl> vvl;
typedef vector<bool> vb;

const int maxn = 15;

int a[maxn];
int t[maxn];
int n, r, cnt;
vector<vi> v;

int main() {
    // FRead();
    Rep(i, maxn+1) a[i] = i + 1;
    while(~scanf("%d%d", &n, &r)) {
        int nn = 1 << n;
        vi p; v.cl();
        For(i, 1, nn) {
            cnt = 0;
            Rep(j, n) {
                if(i & (1 << j)) t[cnt++] = a[j];
            }
            if(cnt == r) {
                p.cl();
                for(int j = cnt - 1; j >= 0; j--) p.pb(t[j]);
                v.pb(p);
            }
        }
        sort(v.begin(), v.end());
        for(int i = v.size() - 1; i >= 0; i--) {
            Rep(j, r) {
                printf("%d", v[i][j]);
            }
            printf("
");
        }
    }
    RT 0;
}