AjO7m4 - Online C++0x Compiler & Debugging Tool

#include <bits/stdc++.h>

using namespace std;
#define int long long
#define yes cout << "YES\n";
#define no cout << "NO\n";


void FastIO(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
}

void solve(){
    string str;
    cin >> str;

    int n = str.size();

    if(n < 26){
        cout << -1;
        return;
    }

    bool ok = false;
    int idx = -1;

    for(int i = 0; i + 26 <= n; i++){
        map<char,int> freq;
        int qcnt = 0;
        bool check = true;

        for(int j = i; j < i + 26; j++){
            if(str[j] != '?'){
                freq[str[j]]++;
                if(freq[str[j]] > 1){
                    check = false;
                    break;
                }
            }
            else qcnt++;
        }

        if(check && (int)freq.size() + qcnt == 26){
            ok = true;
            idx = i;
            break;
        }
    }

    if(!ok){
        cout << -1;
        return;
    }

    string res = str.substr(idx, 26);
    int fr[26] = {0};
    for(char c : res){
        if(c != '?')
            fr[c - 'A']++;
    }

    vector<char> remain;
    for(int k = 0; k < 26; k++){
        if(fr[k] == 0)
            remain.push_back(char('A' + k));
    }

    int it = 0;
    for(char &c : res){
        if(c == '?')
            c = remain[it++];
    }

    for(int j = 0; j < 26; j++){
        str[idx + j] = res[j];
    }

    for(char &c : str){
        if(c == '?') c = 'A';
    }

    cout << str;
}


signed main(){
    FastIO();

    int t = 1;
    //cin >> t;

    while (t--){
        solve();
    }
    return 0;
}