permutation

#include <vector>
#include <iostream>

using namespace std;

void printVec(vector<int>& vec){
	for(auto& ele : vec){
		cout << ele << " ";
	}
	cout << "\n";
}

void permute(vector<int>& vec, int idx){
	if(idx >= vec.size()){
		printVec(vec);
		return;
	}
	for(int i = idx; i < vec.size(); i++){
		swap(vec[i], vec[idx]);
		permute(vec, idx+1);
		swap(vec[i], vec[idx]);
	}
}

auto main() ->int{
	vector<int> a { 1,2,3 };
	permute(a, 0);
}