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
#include <bits/stdc++.h>

using namespace std;
int t,n;
string s;
vector <pair <int, int> > values;

void clr()
{
    while(!values.empty())
    {
        values.pop_back();
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin >> t;
    for(int i=0; i<t; i++)
    {
        cin >> n >> s;
        int curr = 0, res = 0, tura = 0;
        clr();
        bool first = true;

        for(int j=0; j<n; j++)
        {
            if(s[j] == '0') curr++;
            else
            {
                if(first)
                {
                    values.push_back(make_pair(2*curr, 1));
                    first = false;
                }
                else values.push_back(make_pair(curr, 2));

                curr = 0;
            }
        }

        values.push_back(make_pair(2*curr, 1));

        sort(values.begin(), values.end());
        for(int j=values.size()-1; j>=0; j--)
        {
            int v = values[j].first;
            int t = values[j].second;

            //cout << v << ' ' << t << ' ' << tura << ' ' << res << endl;
            if(t==1) res+=max(v/2-t*tura,0);
            else res+=max(v-1-t*tura,0);

            if(t==2 && v-t*tura == 1) res++; ///case gdzie mamy pojedyncze pole zdrowe otoczone chorymi

            tura+=t;
        }

        cout << max(n-res,0) << endl;
    }
}