문제
풀이
#include <iostream>
#include <string>
using namespace std;
void solve(void) {
int n; cin >> n;
string s; cin >> s;
for (int i=0; i<=n/2; i++) {
if (s[i] == '?' && s[n-i-1] == '?') s[i] = s[n-i-1] = 'a';
else if (s[i] == '?') s[i] = s[n-i-1];
else if (s[n-i-1] == '?') s[n-i-1] = s[i];
}
cout << s;
}
int main(void) {
ios::sync_with_stdio(false);
cin.tie(nullptr);
solve();
return 0;
}