Cách 1: $\\$

Thời gian: O(n log n)

Bộ nhớ: O(1)$\\$

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

int main() {   
    int T; cin >> T;
    while (T--) {
        int n; cin >> n;
        for (int i = 1; i <= n; i++) {
            string s = bitset<14>(i).to_string();
            cout << s.erase(0, s.find('1')) << " ";
        }
        cout << endl;
    }
}

$\\\\$

Cách 2:

Thời gian: O(n log n)

Bộ nhớ: O(1)$\\$

#include <bits/stdc++.h>  
using namespace std;  
  
string toBinary(int x) {  
    string res = "";  
    while (x > 0) {  
        res = char(x % 2 + '0') + res;  
        x /= 2;  
    }  
    return res;  
}  
  
int main() {      
    int T; cin >> T;  
    while (T--) {  
        int n; cin >> n;  
        for (int i = 1; i <= n; i++) {  
            cout << toBinary(i) << " ";  
        }  
        cout << endl;  
    }  
    return 0;  
}

$\\\\$

Cách 3:$\\$

Thời gian: O(n log n)

Bộ nhớ: O(n log n)$\\$

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

int main() { 
    int T; cin >> T;
    while (T--) {
        int n; cin >> n;
        queue<string> q;
        q.push("1");
        for (int i = 1; i <= n; i++) {
            string s = q.front(); q.pop();
            cout << s << " ";
            q.push(s + "0");
            q.push(s + "1");
        }
        cout << endl;
    }
    return 0;
}