C++ :

#include<bits/stdc++.h>
using namespace std;

int a[100],n,r;
bool f[100];

void print(){
	for(int i = 1;i <= r;i++){
		cout<<a[i]<<" ";
	}
	cout<<endl;
}

void dfs(int k){
	for(int i = 1;i <= n;i++){
		if(f[i] == false && (k == 1 || i > a[k-1])){
			f[i] = true;
			a[k] = i;
			
			if(k == r){
				print();
			}else{
				dfs(k+1);
			}
			f[i] = false;
		}
		
	}
}

int main(){
	cin>>n>>r;
	dfs(1);
}