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
#include <bits/stdc++.h>
using namespace std;
vector<int> v;
int n, t, d;
char a;

int main()
{
  ios_base::sync_with_stdio(0);

  cin >> t;
  int test_num = 0;
  while (t--) {
    test_num++;
    cin >> n;
    v.clear();

    int l = -1;
    int curr = 0;

    for (int i = 0; i < n; i++) {
      cin >> a;
      if (a == '1') {
        if (l == -1) {
          l = curr;
          curr = 0;
        } else {
          if (curr > 0) {
            v.push_back(curr);
            curr = 0;
          }
        }
      } else {
        curr++;
      }
    }

    int r = curr;
    if (r > l) {
      swap(l, r);
    }

    int u = 0;

    sort(v.begin(), v.end());
    d = 0;
    while ((!v.empty() && v.back() - 2 * d > 0) || l - d > 0) {
      int uv = max(v.back() - 2 * d - 1, 1);
      if (v.empty() || l - d >= uv || (l + r) > v.back()) {
        u += l - d;
        l = 0;
        swap(l, r);
        d++;
      } else {
        u += uv;
        if (uv == 1) {
          d++;
        } else {
          d += 2;
        }
        v.pop_back();
      }
    }
    cout << n - u << endl;
  }

  return 0;
}