Toistot

input/code.cpp: In function 'll solve(ll, ll, int)':
input/code.cpp:39:29: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   39 |     if (to_string(b).size() < rep) {
      |         ~~~~~~~~~~~~~~~~~~~~^~~~~

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

vector<vector<ll>> mul = {
    {0},
    {0, 1, 11, 111, 1111, 11111, 111111, 1111111, 11111111, 111111111, 1111111111L, 11111111111L, 111111111111L, 1111111111111L, 11111111111111L, 111111111111111L, 1111111111111111L, 11111111111111111L, 111111111111111111L, 1111111111111111111L},
    {0, 1, 101, 10101, 1010101, 101010101L, 10101010101L, 1010101010101L, 101010101010101L, 10101010101010101L},
    {0, 1, 1001, 1001001, 1001001001L, 1001001001001L, 100100100100100L},
    {0, 1, 10001, 100010001, 1000100010001L},
    {0, 1, 100001, 10000100001L},
    {0, 1, 1000001, 1000001000001L},
    {0, 1, 10000001},
    {0, 1, 100000001},
    {0, 1, 1000000001},
};

string tee_max_pala(ll x, int rep) {
    string s = to_string(x);
    if (s.size() % rep == 0) {
        return s.substr(0, s.size() / rep);
    } else {
        return string(s.size() / rep, '9');
    }
}
string tee_min_pala(ll x, int rep) {
    string s = to_string(x);
    if (s.size() % rep == 0) {
        return s.substr(0, s.size() / rep);
    } else {
        return '1' + string(s.size() / rep, '0');
    }
}

ll solve(ll a, ll b, int rep) {
    if (to_string(b).size() < rep) {
        return 0;
    }
    string min_pala = tee_min_pala(a, rep);
    string max_pala = tee_max_pala(b, rep);
    ll min_i = stol(min_pala);
    ll max_i = stol(max_pala);
    if (max_i * mul[max_pala.size()][rep] > b) {
        max_i -= 1;
    }
    if (min_i * mul[min_pala.size()][rep] < a) {
        min_i += 1;
    }
    ll num = (max_i >= min_i ? max_i + 1 - min_i : 0);
    return num;
}

// ll laske(ll a, ll b, int rep,)
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    int good_reps[] = {2, 3, 5, 7};
    int bad_reps[] = {6, 10, 14, 15};
    int t;
    cin >> t;
    for (int i = 0; i < t; ++i) {
        ll a, b;
        cin >> a >> b;
        ll ret = 0;
        for (int rep: good_reps) {
            ret += solve(a, b, rep);
        }
        for (int rep: bad_reps) {
            ret -= solve(a, b, rep);
        }
        cout << ret << endl;
    }

    return 0;
}

Test 1

Group: 1, 2, 3, 4

Verdict: ACCEPTED

Test 2

Group: 2, 3, 4

Verdict: ACCEPTED

Test 3

Group: 3, 4

Verdict: ACCEPTED

Test 4

Group: 4

Verdict: WRONG ANSWER

Test 5

Group: 1, 2, 3, 4

Verdict: ACCEPTED

Test 6

Group: 4

Verdict: WRONG ANSWER