【題解】Codeforces 1379A. Acacius and String

#include <iostream>
using namespace std;
 
int T, n;
string s, t = "abacaba";
 
int main() {
    cin >> T;
    while (T--){
        cin >> n;
        cin >> s;
        int cnt = 0;
        int pos = -1;
        for (int i = 0; i < n-6; i++){
            bool flag[2] = {true, true};
            for (int j = 0; j < 7; j++){
                if (s[i+j] != t[j]){
                    flag[0] = false;
                    if (s[i+j] != '?'){
                        flag[1] = false;
                        break;
                    }
                }
            }
            if (flag[0]) cnt++;
            if (flag[1]){
                if (i >= 6 && s.substr(i-6, 6) == t.substr(0, 6)) continue;
                if (i >= 4 && s.substr(i-4, 4) == t.substr(0, 4)) continue;
                if (n-i-6 > 4 && s.substr(i+7, 4) == t.substr(3, 4)) continue;
                if (n-i-6 > 6 && s.substr(i+7, 6) == t.substr(1, 6)) continue;
                pos = i;
            }
        }
        if (cnt > 1) cout << "No\n";
        else if (cnt == 1){
            cout << "Yes\n";
            for (int i = 0; i < n; i++){
                if (s[i] != '?') cout << s[i];
                else cout << 'd';
            }
            cout << "\n";
        }
        else if (pos >= 0){
            for (int i = 0; i < 7; i++){
                s[pos+i] = t[i];
            }
            cout << "Yes\n";
            for (int i = 0; i < n; i++){
                if (s[i] != '?') cout << s[i];
                else cout << 'd';
            }
            cout << "\n";
        }
        else cout << "No\n";
    }
}