Submission #865650

# Submission time Handle Problem Language Result Execution time Memory
865650 2023-10-24T13:06:22 Z azimanov Sequence (BOI14_sequence) C++17
67 / 100
401 ms 69580 KB
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

template<int mod>
class Modular {
public:
    int val;
    Modular() : val(0) {}
    Modular(int new_val) : val(new_val) {
    }
    friend Modular operator+(const Modular& a, const Modular& b) {
        if (a.val + b.val >= mod) return a.val + b.val - mod;
        else return a.val + b.val;
    }
    friend Modular operator-(const Modular& a, const Modular& b) {
        if (a.val - b.val < 0) return a.val - b.val + mod;
        else return a.val - b.val;
    }
    friend Modular operator*(const Modular& a, const Modular& b) {
        return 1ll * a.val * b.val % mod;
    }
    friend Modular binpow(Modular a, long long n) {
        Modular res = 1;
        for (; n; n >>= 1) {
            if (n & 1) res *= a;
            a *= a;
        }
        return res;
    }
    /* ALTERNATIVE INVERSE FUNCTION USING EXTENDED EUCLIDEAN ALGORITHM
    friend void gcd(int a, int b, Modular& x, Modular& y) {
        if (a == 0) {
            x = Modular(0);
            y = Modular(1);
            return;
        }
        Modular x1, y1;
        gcd(b % a, a, x1, y1);
        x = y1 - (b / a) * x1;
        y = x1;
    }
    friend Modular inv(const Modular& a) {
        Modular x, y;
        gcd(a.val, mod, x, y);
        return x;
    }
    */
    friend Modular inv(const Modular& a) {
        return binpow(a, mod - 2);
    }
    Modular operator/(const Modular& ot) const {
        return *this * inv(ot);
    }
    Modular& operator++() {
        if (val + 1 == mod) val = 0;
        else ++val;
        return *this;
    }
    Modular operator++(int) {
        Modular tmp = *this;
        ++(*this);
        return tmp;
    }
    Modular operator+() const {
        return *this;
    }
    Modular operator-() const {
        return 0 - *this;
    }
    Modular& operator+=(const Modular& ot) {
        return *this = *this + ot;
    }
    Modular& operator-=(const Modular& ot) {
        return *this = *this - ot;
    }
    Modular& operator*=(const Modular& ot) {
        return *this = *this * ot;
    }
    Modular& operator/=(const Modular& ot) {
        return *this = *this / ot;
    }
    bool operator==(const Modular& ot) const {
        return val == ot.val;
    }
    bool operator!=(const Modular& ot) const {
        return val != ot.val;
    }
    bool operator<(const Modular& ot) const {
        return val < ot.val;
    }
    bool operator>(const Modular& ot) const {
        return val > ot.val;
    }
    explicit operator int() const {
        return val;
    }
};

template <int mod>
Modular<mod> any_to_mint(ll a) {
    a %= mod;
    return a < 0 ? a + mod : a;
}

template<int mod>
istream& operator>>(istream& istr, Modular<mod>& x) {
    return istr >> x.val;
}

template<int mod>
ostream& operator<<(ostream& ostr, const Modular<mod>& x) {
    return ostr << x.val;
}

template <int mod = 998244353, int root = 3>
class NTT {
    using Mint = Modular<mod>;
public:
    static vector<int> mult(const vector<int>& a, const vector<int>& b) {
        vector<Mint> amod(a.size());
        vector<Mint> bmod(b.size());
        for (int i = 0; i < a.size(); i++) {
            amod[i] = any_to_mint<mod>(a[i]);
        }
        for (int i = 0; i < b.size(); i++) {
            bmod[i] = any_to_mint<mod>(b[i]);
        }
        vector<Mint> resmod = mult(amod, bmod);
        vector<int> res(resmod.size());
        for (int i = 0; i < res.size(); i++) {
            res[i] = resmod[i].val;
        }
        return res;
    }
    static vector<Mint> mult(const vector<Mint>& a, const vector<Mint>& b) {
        int n = int(a.size()), m = int(b.size());
        if (!n || !m) return {};
        int lg = 0;
        while ((1 << lg) < n + m - 1) lg++;
        int z = 1 << lg;
        auto a2 = a, b2 = b;
        a2.resize(z);
        b2.resize(z);
        nft(false, a2);
        nft(false, b2);
        for (int i = 0; i < z; i++) a2[i] *= b2[i];
        nft(true, a2);
        a2.resize(n + m - 1);
        Mint iz = inv(Mint(z));
        for (int i = 0; i < n + m - 1; i++) a2[i] *= iz;
        return a2;
    }

private:
    static void nft(bool type, vector<Modular<mod>> &a) {
        int n = int(a.size()), s = 0;
        while ((1 << s) < n) s++;
        assert(1 << s == n);
        static vector<Mint> ep, iep;
        while (int(ep.size()) <= s) {
            ep.push_back(binpow(Mint(root), (mod - 1) / (1 << ep.size())));
            iep.push_back(inv(ep.back()));
        }
        vector<Mint> b(n);
        for (int i = 1; i <= s; i++) {
            int w = 1 << (s - i);
            Mint base = type ? iep[i] : ep[i], now = 1;
            for (int y = 0; y < n / 2; y += w) {
                for (int x = 0; x < w; x++) {
                    auto l = a[y << 1 | x];
                    auto r = now * a[y << 1 | x | w];
                    b[y | x] = l + r;
                    b[y | x | n >> 1] = l - r;
                }
                now *= base;
            }
            swap(a, b);
        }
    }
};

const ll inf = 1e18;
const int L = 18;
const int C = 10;
const int N = 1e5 + 10;
const int M = 1e6 + 1e5 + 10;

int cnt_suf[C][M];

ll pw10[L];
int flag[N];
ll dp[(1 << C)][(1 << C)];

int b[N];
int lef[C][N], rig[C][N];
int pref[C][N], suf[C][N];

bool getbit(int mask, int bit) {
    return mask & (1 << bit);
}

ll mask_to_ll(int mask) {
    ll res = 0;
    for (int i = 1; i < C; i++) {
        if (getbit(mask, i)) {
            res = res * 10 + i;
            mask ^= (1 << i);
            break;
        }
    }
    for (int i = 0; i < C; i++) {
        if (getbit(mask, i)) {
            res = res * 10 + i;
        }
    }
    return res;
}

int vec_to_mask(const vector<int>& vec) {
    int mask = 0;
    for (int i : vec) {
        mask |= (1 << i);
    }
    return mask;
}

void init() {
    {
        for (int x = M - 1; x >= 1; x /= 10) {
            cnt_suf[x % 10][M - 1]++;
        }
    }
    for (int i = M - 2; i >= 1; i--) {
        int mask = 0;
        for (int x = i; x >= 1; x /= 10) {
            mask |= (1 << (x % 10));
        }
        for (int c = 0; c < C; c++) {
            if (getbit(mask, c)) {
                cnt_suf[c][i] = cnt_suf[c][i + 1] + 1;
            } else {
                cnt_suf[c][i] = 0;
            }
        }
    }

    pw10[0] = 1;
    for (int i = 1; i < L; i++) {
        pw10[i] = pw10[i - 1] * 10;
    }

    flag[0] = (1 << 0);
    for (int i = 1; i <= N - 1; i++) {
        for (int j = i; j >= 1; j /= 10) {
            flag[i] |= (1 << (j % 10));
        }
    }

    for (int i = 0; i < (1 << C); i++) {
        for (int j = 0; j < (1 << C); j++) {
            dp[i][j] = inf;
        }
    }
    for (int mask = 0; mask < (1 << C); mask++) {
        for (int last = 0; last < C && last != 9; last++) {
            if (mask == 0 && last == 0) {
                continue;
            }
            int pref_mask = mask | (1 << last);
            int suf_mask = mask | (1 << (last + 1));
            if (mask_to_ll(mask) != 0 || last != 0) {
                dp[pref_mask][suf_mask] = min(dp[pref_mask][suf_mask], mask_to_ll(mask == 1 ? 3 : mask) * 10 + last);
            }

            pref_mask = mask | (1 << last) | (1 << 9);
            suf_mask = mask | (1 << (last + 1)) | (1 << 0);
            dp[pref_mask][suf_mask] = min(dp[pref_mask][suf_mask], mask_to_ll(mask == 1 ? 3 : mask) * 100 + last * 10 + 9);
        }
    }
    for (int i = (1 << C) - 1; i >= 0; i--) {
        for (int j = (1 << C) - 1; j >= 0; j--) {
            for (int c = 0; c < C; c++) {
                dp[i][j] = min(dp[i][j], dp[i | (1 << c)][j]);
                dp[i][j] = min(dp[i][j], dp[i][j | (1 << c)]);
            }
        }
    }
}

void calc_lef_rig(int k) {
    const int n = 100'000;
    for (int c = 0; c < C; c++) {
        vector<int> p(n, 0);
        vector<int> q(k, 0);
        for (int i = 0; i < n; i++) {
            p[i] = getbit(flag[i], c);
        }
        for (int i = 1; i <= k; i++) {
            q[k - i] = b[i] == c;
        }
        auto r = NTT<998244353, 3>::mult(p, q);
        for (int i = 0; i < n; i++) {
            lef[c][i] = r[i];
            rig[c][i] = r[i + k - 1];
        }
    }
}

void calc_pref_suf(int k) {
    for (int c = 0; c < C; c++) {
        pref[c][0] = 0;
        suf[c][k + 1] = 0;
    }
    for (int i = 1; i <= k; i++) {
        for (int c = 0; c < C; c++) {
            pref[c][i] = pref[c][i - 1];
        }
        pref[b[i]][i]++;
    }
    for (int i = k; i >= 1; i--) {
        for (int c = 0; c < C; c++) {
            suf[c][i] = suf[c][i + 1];
        }
        suf[b[i]][i]++;
    }
}

ll solve(int k) {
    calc_lef_rig(k);
    calc_pref_suf(k);

    const int n = 100'000;
    ll ans = inf;

    for (int i = 0; i < n; i++) {
        if (i + k - 1 < n) {
            int need = 0;
            for (int c = 0; c < C; c++) {
                if (rig[c][i] != pref[c][k]) {
                    need |= (1 << c);
                }
            }
            if (need == 0) {
                if (i == 0) {
                    ans = min(ans, ll(n));
                } else {
                    ans = min(ans, ll(i));
                }
            } else {
                if (need == 1) {
                    need = 3;
                }
                ll x = mask_to_ll(need);
                ans = min(ans, x * pw10[to_string(i + k - 1).size()] + i);
            }
        } else {
            int len_pref = n - i;
            int len_suf = k - len_pref;
            int need_pref = 0, need_suf = 0;
            for (int c = 0; c < C; c++) {
                if (rig[c][i] != pref[c][len_pref]) {
                    need_pref |= (1 << c);
                }
                if (lef[c][len_suf - 1] != suf[c][len_suf]) {
                    need_suf |= (1 << c);
                }
            }
            if (dp[need_pref][need_suf] != inf) {
                ans = min(ans, dp[need_pref][need_suf] * n + i);
            }
        }
    }
    return ans;
}

ll solve_same(int k) {
    for (int i = 1; i <= k - 1; i++) {
        if (b[i] != b[i + 1]) {
            return inf;
        }
    }
    for (int n = 1; n + k - 1 <= M - 1; n++) {
        if (cnt_suf[b[1]][n] >= k) {
            return n;
        }
    }
    return -1;
}

ll slow(int k) {
    for (int n = 1; n <= 1000; n++) {
        bool ok = true;
        for (int i = 1; i <= k; i++) {
            ok &= getbit(flag[n + i - 1], b[i]);
        }
        if (ok) {
            return n;
        }
    }
    return -1;
}

void stress() {
    mt19937 rnd;
    while (true) {
        int k = rnd() % 10 + 1;
        for (int i = 1; i <= k; i++) {
            b[i] = rnd() % C;
        }
        ll res = slow(k);
        if (res == -1) {
            continue;
        }
        ll ans = solve(k);
        if (ans == res) {
            cout << "OK" << endl;
        } else {
            cout << "WA\n";
            cout << k << "\n";
            for (int i = 1; i <= k; i++) {
                cout << b[i] << " ";
            }
            cout << "\n\n";
            cout << ans << " " << res << "\n";
            break;
        }
    }
    exit(0);
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif

    init();

    // stress();

    // cout << dp[vec_to_mask({1, 2, 3})][vec_to_mask({9, 0, 1, 4})] << "\n";

    int k;
    cin >> k;
    for (int i = 1; i <= k; i++) {
        cin >> b[i];
    }
//    k = 100'000;
//    for (int i = 1; i <= k; i++) {
//        b[i] = 1;
//    }

    cout << min(solve(k), solve_same(k)) << "\n";

#ifdef LOCAL
    cout << "\nTime elapsed: " << double(clock()) / CLOCKS_PER_SEC << " s.\n";
#endif
}

Compilation message

sequence.cpp: In instantiation of 'static std::vector<int> NTT<mod, root>::mult(const std::vector<int>&, const std::vector<int>&) [with int mod = 998244353; int root = 3]':
sequence.cpp:304:46:   required from here
sequence.cpp:125:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |         for (int i = 0; i < a.size(); i++) {
      |                         ~~^~~~~~~~~~
sequence.cpp:128:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  128 |         for (int i = 0; i < b.size(); i++) {
      |                         ~~^~~~~~~~~~
sequence.cpp:133:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  133 |         for (int i = 0; i < res.size(); i++) {
      |                         ~~^~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 210 ms 69140 KB Output is correct
2 Correct 207 ms 69284 KB Output is correct
3 Correct 207 ms 69148 KB Output is correct
4 Correct 210 ms 69264 KB Output is correct
5 Correct 206 ms 69160 KB Output is correct
6 Correct 207 ms 69252 KB Output is correct
7 Correct 206 ms 69032 KB Output is correct
8 Correct 231 ms 69368 KB Output is correct
9 Correct 206 ms 69136 KB Output is correct
10 Correct 207 ms 69100 KB Output is correct
11 Correct 215 ms 69360 KB Output is correct
12 Correct 208 ms 69288 KB Output is correct
13 Correct 206 ms 69148 KB Output is correct
14 Correct 208 ms 69096 KB Output is correct
15 Correct 209 ms 69068 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 206 ms 69280 KB Output is correct
2 Correct 210 ms 69316 KB Output is correct
3 Correct 207 ms 69268 KB Output is correct
4 Correct 206 ms 69068 KB Output is correct
5 Correct 215 ms 69276 KB Output is correct
6 Correct 207 ms 69248 KB Output is correct
7 Correct 208 ms 69204 KB Output is correct
8 Correct 211 ms 69200 KB Output is correct
9 Correct 206 ms 69084 KB Output is correct
10 Correct 206 ms 69248 KB Output is correct
11 Correct 214 ms 69384 KB Output is correct
12 Correct 206 ms 69232 KB Output is correct
13 Correct 206 ms 69056 KB Output is correct
14 Correct 213 ms 69340 KB Output is correct
15 Correct 205 ms 69028 KB Output is correct
16 Correct 205 ms 69076 KB Output is correct
17 Correct 207 ms 69116 KB Output is correct
18 Correct 207 ms 69284 KB Output is correct
19 Correct 206 ms 69148 KB Output is correct
20 Correct 216 ms 69340 KB Output is correct
21 Correct 207 ms 69032 KB Output is correct
22 Correct 206 ms 69068 KB Output is correct
23 Correct 207 ms 69316 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 206 ms 69104 KB Output is correct
2 Correct 207 ms 69396 KB Output is correct
3 Correct 214 ms 69580 KB Output is correct
4 Correct 206 ms 69368 KB Output is correct
5 Correct 207 ms 69440 KB Output is correct
6 Correct 213 ms 69240 KB Output is correct
7 Correct 358 ms 68972 KB Output is correct
8 Correct 367 ms 68840 KB Output is correct
9 Correct 366 ms 69204 KB Output is correct
10 Correct 372 ms 68968 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 220 ms 69128 KB Output is correct
2 Correct 230 ms 69268 KB Output is correct
3 Correct 218 ms 69172 KB Output is correct
4 Correct 213 ms 69304 KB Output is correct
5 Correct 401 ms 68796 KB Output is correct
6 Correct 227 ms 69196 KB Output is correct
7 Correct 212 ms 69260 KB Output is correct
8 Correct 213 ms 69068 KB Output is correct
9 Correct 210 ms 69028 KB Output is correct
10 Correct 206 ms 69224 KB Output is correct
11 Correct 362 ms 69084 KB Output is correct
12 Correct 361 ms 69248 KB Output is correct
13 Correct 207 ms 69132 KB Output is correct
14 Correct 206 ms 69064 KB Output is correct
15 Correct 206 ms 69188 KB Output is correct
16 Correct 208 ms 69148 KB Output is correct
17 Correct 206 ms 69344 KB Output is correct
18 Correct 207 ms 69148 KB Output is correct
19 Correct 212 ms 69068 KB Output is correct
20 Correct 208 ms 69348 KB Output is correct
21 Correct 206 ms 69192 KB Output is correct
22 Correct 206 ms 69284 KB Output is correct
23 Correct 207 ms 69204 KB Output is correct
24 Correct 207 ms 69052 KB Output is correct
25 Correct 208 ms 69288 KB Output is correct
26 Correct 206 ms 69068 KB Output is correct
27 Correct 207 ms 69220 KB Output is correct
28 Correct 209 ms 69312 KB Output is correct
29 Correct 207 ms 69452 KB Output is correct
30 Correct 208 ms 69436 KB Output is correct
31 Correct 208 ms 69320 KB Output is correct
32 Correct 357 ms 68924 KB Output is correct
33 Correct 360 ms 68752 KB Output is correct
34 Correct 360 ms 69188 KB Output is correct
35 Correct 361 ms 69272 KB Output is correct
36 Incorrect 357 ms 68912 KB Output isn't correct
37 Halted 0 ms 0 KB -