Revise paste Untitled

#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <algorithm>
using namespace std;
typedef long long ll;
vector<ll> v;

map<pair<int, ll>, int> dp;
map<pair<int, ll>, pair<int, ll>> backtrack;
map<pair<int, ll>, ll> number;
int rec(int at, ll x) {
    if(x == 0) {
        return 0;
    }
    if(dp.count(make_pair(at, x))) {
        return dp[make_pair(at, x)];
    }
    int res = 2e9;
    int idx = lower_bound(v.begin(), v.end(), x) - v.begin();
    vector<pair<int, ll>> sorted_rec;
    if(idx < 0 or idx >= v.size()) {
        idx = v.size() - 1;
    }
    for(int i = idx; i >= max(0, idx - 6); i--) {
        if(x - v[i] >= 0) {
            sorted_rec.push_back(make_pair(rec(i, x - v[i]) + 1, i));
        }
    }
    sort(sorted_rec.begin(), sorted_rec.end());
    res = sorted_rec[0].first;
    backtrack[make_pair(at, x)] = make_pair(sorted_rec[0].second, x - v[sorted_rec[0].second]);
    number[make_pair(at, x)] = v[sorted_rec[0].second];
    
    return dp[make_pair(at ,x)] = res;
}

int main()
{
    ll n;
    cin >> n;
    
    for(int i = 1; i <= 9; i++) {
        ll num = i;
        for(int j = 0; j < 12; j++) {
            if(num <= n) {
                v.push_back(num);
            }
            num = (num * 10) + i;
        }
    }
    sort(v.begin(), v.end());
    int ret =  rec(v.size() - 1, n);

for(int i = 0; i < v.size(); i++) {
        for(ll j = 0; j <= 20; j++) {
            if(v[i]  *j == n) {
                if(ret > j) {
                    cout << j << " ";
                    for(int k =0 ; k < j; k++) {
                        cout << v[i] << " ";
                    }
                    return 0;
                }
            }
        }
    }
    cout << ret << endl;
    pair<int, ll> at = make_pair(v.size() - 1, n);
    while(true) {
        if(at.second == 0) {
            break;
        }
        cout << number[at] << " ";
        at = backtrack[at];
    }
    return 0;
}
// 2222222222
// 22222222222