1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

bool compare(pair<float, float> a, pair<float, float> b) {
    return a.first/a.second >= b.first/b.second;
}

void empty(vector<pair<int, int>>& a, int& s) {
    for (int i = a.size() - 1; i > -1; i--) {
        if (a[i].second > 0)
            s += a[i].second;
        a[i].first -= a[i].second;
        if (a[i].first <= 0 || a[i].second <= 0)
            a.erase(a.begin() + i);
        if (a[i].first == 1 && a[i].second == 2)
            a[i].second = 1;
    }
}

void solve() {
    int n;
    string miasto;
    cin >> n;
    cin >> miasto;
    miasto = "2" + miasto + "2";
    vector<pair<int, int>> gaps;
    bool saving = false;
    int sum = 0;
    for (int i = 0; i < n + 2; i++) {
        if (miasto[i] == '1')
            sum++;
        if (!saving) {
            if (miasto[i] == '0') {
                gaps.push_back(pair<int, int>(1, miasto[i - 1] == '1'));
                saving = true;
            }
        } else {
            if (miasto[i] == '0')
                gaps.back().first++;
            else if (miasto[i] == '1') {
                gaps.back().second++;
                saving = false;
            } else if (miasto[i] == '2') {
                saving = false;
            }
        }
        if (gaps.size() > 0 && gaps.back().first == 1 && gaps.back().second == 2)
            gaps.back().second = 1;
    }
    sort(gaps.begin(), gaps.end(), [] (auto a, auto b) {return compare(a, b);});
    while (gaps.size() > 0) {
        gaps[0].first--;
        gaps[0].second--;
        empty(gaps, sum);
        sort(gaps.begin(), gaps.end(), [] (auto a, auto b) {return compare(a, b);});
    }
    cout << sum << "\n";
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    int t, n;
    string miasto;
    cin >> t;
    for (int i = 0; i < t; i++) {
        int puste = 0;
        bool grouping = false;
        solve();
    }
}