func_code_string: #include <bits/stdc++.h>   using namespace std;   void solve() {     int n;     cin >> n;     string a, b;     cin >> a >> b;     vector<int> ans;     int l = 0, r = n - 1;     for (int i = 0; i < n; i++) {       if (!(i & 1)) {         if (a[l] == b[n - i - 1]) ans.push_back(1);         ans.push_back(max(l, r) - min(l, r) + 1);       } else {         if (a[l] != b[n - i - 1]) ans.push_back(1);         ans.push_back(max(l, r) - min(l, r) + 1);       }       swap(l, r);       if (r > l)         r--;       else         r++;     }     cout << ans.size() <<    ;     for (auto x : ans) cout << x <<    ;     cout <<   n ;     return;   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     int t;     cin >> t;     while (t--) {       solve();     }     return 0;   }   