Binary Generator

//Trần Việt Anh - 12/3/2019 - 10:27 AM
#include<iostream>

using namespace std;

int main()
{
    int n; cin >> n;
    string s = "";
    for (int i = 0; i < n; i++)
        s += "0";
    int i = s.length() - 1;
    do
    {
        i = s.length() - 1;
        cout << s << endl;
        while (s[i] == '1' && i >= 0) i--;
        if (i >= 0)
        {
            s[i] = '1';
            for (int j = i + 1; j < s.length(); j++)
                s[j] = '0';
        }
    }
    while (i >= 0);
}