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
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(){

    int z;
    cin>>z;

    while(z--){
        int n;
        cin>>n;

        string a;
        cin>>a;

        int c = 0;
        vector<pair<int, int>> V;
        for(int i=0; i<n; i++){
            if(a[i]=='0')
                c++;
            if(a[i]=='1'&&c>0){
                if(i-c==0)
                    V.push_back({c, 1});
                else
                    V.push_back({c, 0});
            c=0;
            }
        }
        if(a[n-1]=='0')
            V.push_back({c, 1});

        sort(V.rbegin(), V.rend());

        int sz = 0;
        int aa = 0;

        for(int i=0; i<V.size(); i++){
            if(V[i].second==1 && V[i].first - 1*i>=0)
                sz += V[i].first - 1*i;
            if(V[i].second==0){
                if(V[i].first - 2*(i+aa) == 1)
                    sz+=V[i].first - 2*(i+aa);
                else if(V[i].first - 2*(i+aa) - 1>=0)
                    sz+=V[i].first - 2*(i+aa) - 1;

                aa++;
            }
        }

        cout<<n-sz<<endl;
    }

    return 0;
}