Sum of ones

#include <iostream>
#include <vector>
#include <string>
#include <math.h>
using namespace std;



long long count(long long n){
    long long pair = 2;;
    long long count = 0 ;
    while ((pair/2) < n){
        count += ((long long)(n/(pair)) * (long long)(pair/2));
        if ((n  % pair) > (pair/2) )
            count += (n % pair) - (long long)(pair / 2);
        pair *= 2;
    }
    return count ;
}

int main() {
    long long n;
    cin >> n;
    
    cout << count(n+1) << endl;

}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

Verdict: ACCEPTED