For a non negative integer in the range 0 = i = n write a C++ programming to calculate the number of 1's in their binary representation and return them as an array

#include <iostream>
#include <vector>
using namespace std;

vector countBits(int num) {
    	vector res;
        for (int i = 0; i <= num; ++i) {
            res.push_back(0);
        }

        for (int i = 1; i <= num; ++i) {
            res[i] = res[i / 2] + i % 2;
        }

        return res;
    }
    
int main()
{
    int n = 4;
    vector result;
	cout << "Original number: " << n << endl; 
	result = countBits(n);
	for (int x : result) 
        cout << x << " "; 
    n = 7;    
	cout << "\nOriginal number: " << n << endl; 
	result = countBits(n);
	for (int x : result) 
        cout << x << " ";   
    return 0;
}