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
#include <bits/stdc++.h>
#define int long long
#define mp make_pair
#define pb push_back
#define ld long double
#define pii pair<int,int>
#define sz(x) (int)x.size()
#define piii pair<pii,pii>
#define precise cout<<fixed<<setprecision(10)
#define st first
#define nd second
#define ins insert
#define vi vector<int>
#define BOOST ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
using namespace std;
const int MAX=1e5+5;
const int inf=1e18+9;
char a[MAX];
void solve(){
	int n;
	cin>>n;
	int zeros=0;
	for (int i=1;i<=n;i++)cin>>a[i],zeros+=(a[i]=='0');
	multiset<int>ones,twos;ones.clear();twos.clear();
	
	for (int i=1;i<=n;i++){
		int j=i;
		if (a[i]!='0')continue;
		while (j+1<=n && a[j+1]=='0'){
			j++;
		}	
		if (i==1 || j==n)ones.ins(j-i+1);
		else twos.ins(j-i+1);
		i=j;
	}
	int odj1=0,odj2=0,ans=0;
	for (int tempo=1;tempo<=n;tempo++){
		while (sz(twos) && *twos.begin()<=odj2)twos.erase(twos.find(*twos.begin()));
		while (sz(twos) && *twos.begin()-odj2<=1){
			int x=*twos.begin();
			twos.erase(twos.find(x));
			x-=odj2;
			x+=odj1;
			ones.ins(x);
		}
		while (sz(ones) && *ones.begin()<=odj1)ones.erase(ones.find(*ones.begin()));
	  int as=-inf;
		int bs=-inf;
		if (sz(twos))as=(*twos.rbegin()-odj2);
		if (sz(ones))bs=(*ones.rbegin()-odj1)*2;
		if (as>=bs && as!=-inf){
		  int x=*twos.rbegin();
		  twos.erase(twos.find(x));
		  x--;
		  if (x>0)
		  ones.ins(x-odj2+odj1);
		}
		else if (bs>as && bs!=-inf){
			int x=*ones.rbegin();
			ones.erase(ones.find(x));
		}
		ans+=sz(twos)*2+sz(ones);
		odj1++;
		odj2+=2;
	}
	cout<<ans+n-zeros<<"\n";
}
int32_t main(){
  BOOST;
  int t;
  cin>>t;
  for (int z=0;z<t;z++){
		solve();
  }
  return 0; 
}