Sum of ones

#include <bits/stdc++.h>

void init_code() {
    std::ios_base::sync_with_stdio(0);
    std::cin.tie(0);
    #ifndef ONLINE_JUDGE
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif
}

using namespace std;

void solve() {
    int n;
    cin >> n;

    n += 1;
    
    int res = 0;
    bool flag = true;

    int step = 2;
    while (flag) {
        int tmp = 0;
        tmp += (n / step) * (step / 2);
        tmp += (n % step) % (step / 2);

        res += tmp;

        if (tmp == 0) {
            flag = false;
        }
        step *= 2;
    }

    cout << res << '\n';

    /*
    int ch = n;
    int len = 0;
    while (ch != 0) {
        ch /= 2;
        len++;
    }
    for (int i = n; i >= 0; --i) {
        int x = i;
        string res = "";
        while (x != 0) {
            if (x % 2 == 0) {
                res += "0";
            } else {
                res += "1";
            }
            x /= 2;
        }
        while (res.length() != len) {
            res += "0";
        }
        reverse(res.begin(), res.end());
        cout << res << '\n';
    }*/

}


signed main() {
    init_code();
    int t = 1;
    //cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: RUNTIME ERROR

Test 3

Verdict: ACCEPTED

Test 4

Verdict: RUNTIME ERROR

Test 5

Verdict: RUNTIME ERROR

Test 6

Verdict: RUNTIME ERROR

Test 7

Verdict: ACCEPTED

Test 8

Verdict: RUNTIME ERROR

Test 9

Verdict: RUNTIME ERROR

Test 10

Verdict: RUNTIME ERROR

Test 11

Verdict: RUNTIME ERROR

Test 12

Verdict: RUNTIME ERROR

Test 13

Verdict: RUNTIME ERROR

Test 14

Verdict: RUNTIME ERROR

Test 15

Verdict: RUNTIME ERROR

Test 16

Verdict: RUNTIME ERROR

Test 17

Verdict: RUNTIME ERROR

Test 18

Verdict: RUNTIME ERROR

Test 19

Verdict: RUNTIME ERROR

Test 20

Verdict: RUNTIME ERROR

Test 21

Verdict: RUNTIME ERROR