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
#include<bits/stdc++.h>

using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define ST first
#define ND second
#define SIZE(a) ((int)a.size())

void solve() {
    int n;
    string s;
    cin >> n >> s;
    int d = 0;
    vector<pii> v;
    bool start = true;
    int res = 0;
    for(int i=0; i < SIZE(s); i++) {
        char c = s[i];
        if(c == '0') {
            d++;
        } else {
            res++;
            if(start) {
                v.push_back({2*d, d});
                start = false;
            } else {
                v.push_back({d, d});
            }
            d = 0;
        }
    }
    v.push_back({2*d, d});
    sort(v.begin(), v.end(), greater<pii>());
    int day=0;
    for(pii x : v) {
        // cout << x.first << " " << x.second << "\n";
        if(x.first == x.second) {
            int diff = x.first - 2*day;
            if(diff > 2) {
                res+=2*day+1;
                day+=2;
            } else if(diff > 0) {
                res+=x.first-1;
                day+=1;
            } else {
                res+=x.first;
            }
        } else {
            int diff = x.second - day;
            if(diff > 0) {
                res+=day;
                day+=1;
            } else {
                res+=x.second;
            }
        }
    }
    cout << res << "\n";
}

int main() {
    ios_base::sync_with_stdio(0);
    int t;
    cin >> t;
    while(t--) {
        solve();
    }
}