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
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

using namespace std;

typedef uint32_t ul;
typedef int32_t l;
typedef uint64_t ull;
typedef int64_t ll;

const l INF = 1000000000 + 9;
const ll MOD = 123456789;
const l PRIME = 200003;
const ll L_INF = 1000000000000000000LL + 7;
const double EPS = 1e-5;

#define FOR(x, y, z) for (ll z = x; z < y; z++)
#define FORE(x, y, z) for (ll z = x; z <= y; z++)
#define FORD(x, y, z) for (ll z = x; z > y; z--)
#define FORDE(x, y, z) for (ll z = x; z >= y; z--)
#define REP(x, y) for (ll y = 0; y < x; y++)
#define ALL(...) (__VA_ARGS__).begin(), (__VA_ARGS__).end()

#define PF push_front
#define POF pop_front
#define PB push_back
#define POB pop_back
#define MP make_pair
#define FS first
#define SC second

ll n, num_tests, cnt=1;
ll best = 0;
char last = 'o';
bool first = true;
vector<ll> one, two;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);

    cin >> num_tests;

    while(num_tests--)
    {
        best = 0, cnt = 1;
        last = 'o';
        first = true;
        one.clear(), two.clear();
        
        cin >> n;
        FOR(0, n+1, i)
        {
            char a;
            if(i < n)
                cin >> a;
            else
                a = '1';

            if(i != 0)
            {
                if(a != last && a == '1')
                {
                    if(first || i == n)
                    {
                        one.PB(cnt);
                        first = false;
                    }
                    else
                        two.PB(cnt);
                    cnt = 1;
                }
                else if(a != last && a == '0')
                    cnt = 1;
                else
                    cnt++;
            }

            else if(i == 0 && a == '1')
                first = false;

            last = a;
        }

        sort(ALL(one), greater<ll>());
        sort(ALL(two), greater<ll>());

        /*for(auto u: one)
            cout << u << " ";
        cout << "\n------------\n";
        for(auto u: two)
            cout << u << " ";
        cout << "\n------------\n";*/

        ll curr = 0, n_curr;
        FORE(0, (ll)one.size(), i)
        {   
            if(i)
                curr += max(one[i-1]-(i-1LL), 0LL);
            n_curr = curr;
            FORE(0, (ll)two.size(), j)
            {
                if(j)
                    if(two[j-1]-2LL*(i+2LL*(j-1LL)) > 0)
                        n_curr += max(two[j-1]-2LL*(i+2LL*(j-1LL))-1LL-1LL, 0LL)+1LL;
                
                /*if(n_curr > best)
                    cout << i << " " << j << "\n";*/
                best = max(best, n_curr);
            }
        }

        cout << n-best << "\n";
    }
}