Lista

#include <bits/stdc++.h>

using namespace std;

vector<string> nums;



int main(){

    int n;
    cin >> n;
    vector<string> nums(n);
    for(string&s:nums)cin>>s;
    string p;

    for(string& s : nums){

        int ss = (int)s.size();
        int ps = (int)p.size();

        if(ps > ss){
            cout << "IMPOSSIBLE\n";
            return 0;
        }

        if(ps < ss){
            for(int i = 0; i < ss; ++i){
                if(s[i]=='?')s[i] = '0' + (i==0);
            }
        }
        else{

            bool found = 0;

            for(int i = 0; i < ss; ++i){
                if(s[i] != '?')continue;

                for(int d = (i==0); d <= 9; ++d){
                    s[i] = '0' + d;
                    string temp = s;
                    for(int j = i + 1; j < ss; ++j){
                        if(temp[j]=='?')temp[j]='9';
                    }
                    if(temp > p){
                        found = 1;
                        break;
                    }
                }
            }

            if(!found){
                cout << "IMPOSSIBLE\n";
                return 0;
            }
        }

        // if(ps == ss && s <= p){
            // cout << "IMPOSSIBLE\n";
            // return 0;
        // }

        p = s;
    }

    for(string x : nums)cout << x << "\n";

}

Test 1

Group: 1, 2, 3

Verdict: ACCEPTED

Test 2

Group: 2, 3

Verdict: ACCEPTED

Test 3

Group: 3

Verdict: ACCEPTED

Test 4

Group: 1, 2, 3

Verdict: ACCEPTED

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED

Test 6

Group: 1, 2, 3

Verdict: ACCEPTED

Test 7

Group: 1, 2, 3

Verdict: ACCEPTED

Test 8

Group: 3

Verdict: WRONG ANSWER

Test 9

Group: 3

Verdict: ACCEPTED

Test 10

Group: 3

Verdict: ACCEPTED