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
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
/*
PANDEMIA
ERYK MARCINIAK B)
*/

#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;

int ile;

void solve()
{
    bool bul=0;
    char a;
    int n=0,wyn=0,dp=0;
    vector< pair<int,int> >t;

    cin >> n;
    cin >> a;
    if(a=='0')
    {
        dp=1;
        bul=1;
    }
    for(int i=1;i<n;i++)
    {
        cin >> a;
        if(a=='0')
            dp++;
        else if(dp)
        {
            if(!bul)
                t.push_back({dp,0});
            else
                t.push_back({dp*2,1});
            bul=0;
            dp=0;
        }
    }
    if(dp)
        t.push_back({dp*2,1});
    sort(t.rbegin(),t.rend());

    /*for(int i=0;i<t.size();i++)
    {
        cout << t[i].fi << " " << endl;
    }*/

    int time=0;

    for(int i=0;i<t.size();i++)
    {
        if(t[i].se==1 && t[i].fi/2-time>0)
        {
            wyn=wyn+(t[i].fi/2-time);
            time++;
            //cout << "a" << t[i].fi/2-time << endl;
        }
        else
        {
            int pom;
            if(t[i].fi-(time*2)==1) pom=1;
            else pom=t[i].fi-(time*2)-1;
            if(pom>0)
            {
                if(pom==1)
                    time--;
                time+=2;
                wyn+=pom;
                //cout << "pom" << pom << endl;
                //cout << "b" << wyn << endl;
            }
            else break;
        }
    }
    //cout << endl << n << endl << wyn << endl;
    cout << n-wyn << endl;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> ile;
    for(int i=0;i<ile;i++)
        solve();
    return 0;
}