func_code_string: #include <bits/stdc++.h>   using namespace std;   const double Pi = acos(-1.0);   const int MAXN = 1e6 + 5;   int n, m, t;   int v[MAXN];   char s[MAXN];   int main() {     cin >> t;     while (t--) {       cin >> n >> s + 1;       int sum1 = 0, sum2 = 0, now = 0;       for (int i = 1; i <= n * 2; i++) {         if (s[i] ==  1 )           now++;         else {           sum1 += max(now - 1, 0);           now = 0;         }       }       if (now) sum1 += now - 1;       now = 0;       for (int i = 1; i <= n * 2; i++) {         if (s[i] ==  0 )           now++;         else {           sum2 += max(now - 1, 0);           now = 0;         }       }       if (now) sum2 += now - 1;       cout << max(sum1, sum2) << endl;     }   }   