Lista

input/code.cpp: In function 'int main()':
input/code.cpp:28:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 1; i < first.length(); ++i){
                    ~~^~~~~~~~~~~~~~~~
input/code.cpp:43:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(pre.length() > cl)gg();
            ~~~~~~~~~~~~~^~~~
input/code.cpp:44:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(cl > pre.length()){
            ~~~^~~~~~~~~~~~~~
input/code.cpp:35:14: warning: unused variable 'lz' [-Wunused-variable]
         bool lz = 1;
              ^~

#include <iostream>
#include <vector>
#include <string>

using namespace std;
using ll = long long;

void gg(){
    cout << "IMPOSSIBLE\n";
    exit(0);
}

int dig_at_pos(int num, int pos){
    while(pos--)num/=10;
    return num%10;
}

int main(){

    int n;
    cin >> n;
    vector<string> a(n);
    for(auto& x : a){
        cin >> x;
    }
    string first = a[0];
    if(first[0] == '?')first[0] = '1';
    for(int i = 1; i < first.length(); ++i){
        if(first[i] == '?')first[i] = '0';
    }
    a[0] = first;

    for(int i = 1; i < n; ++i){
        
        bool lz = 1;
        bool tight = 1;

        string pre = a[i-1];
        string cur = a[i];

        int cl  = cur.length();

        if(pre.length() > cl)gg();
        if(cl > pre.length()){
            for(int i = 0; i < cl; ++i){
                if(cur[i] == '?')cur[i] = '0' + (i == 0);
            }
        }

        else{
            for(int i = 0; i < cl; ++i){
                if(pre[i] > cur[i] && cur[i] != '?' && tight)gg();
                if(cur[i]=='?'){

                    bool ok = 0;
                    for(int j = i + 1; j < cl; ++j){
                        if(cur[j] > pre[j]){
                            ok = 1;
                            break;
                        }
                        if(cur[j] == '?'){
                            if(pre[j] == '9')continue;
                            ok = 1;
                            break;
                        }
                        break;
                    }

                    if(!ok && pre[i] == '9'){
                        gg();
                    }
                    else{
                        if(ok)cur[i] = pre[i];
                        else cur[i] = pre[i] + 1;
                    }
                }
            }
        }

        a[i] = cur;
    }

    for(int i = 0; i < n; ++i){
        cout << a[i] << "\n";
    }
}

Test 1

Group: 1, 2, 3

Verdict: WRONG ANSWER

Test 2

Group: 2, 3

Verdict: WRONG ANSWER

Test 3

Group: 3

Verdict: WRONG ANSWER

Test 4

Group: 1, 2, 3

Verdict: WRONG ANSWER

Test 5

Group: 1, 2, 3

Verdict: ACCEPTED

Test 6

Group: 1, 2, 3

Verdict: WRONG ANSWER

Test 7

Group: 1, 2, 3

Verdict: ACCEPTED

Test 8

Group: 3

Verdict: WRONG ANSWER

Test 9

Group: 3

Verdict: WRONG ANSWER

Test 10

Group: 3

Verdict: WRONG ANSWER