Submission #1002070

#	Time	Username	Problem	Language	Result	Execution time	Memory
1002070		Nelt	Dabbeh (INOI20_dabbeh)	C++17	100 / 100	1288 ms	91132 KiB

Main

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define endl "\n"
 
using namespace std;
using namespace __gnu_pbds;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template<class T> using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
const ll p = 37, lg = 20;
const ll N = 5e5 + 5;
ll mod[] = {998244353, (ll)1e9 + 9};
long long pw[3][N], invpw[3][N];
ll up[lg][N];
ll binpow(ll n, ll p, ll mod)
{
    n %= mod;
    ll ans = 1;
    while (p)
    {
        ans = 1ll * ans * (p & 1 ? n : 1) % mod;
        p >>= 1;
        n = 1ll * n * n % mod;
    }
    return ans;
}
ll inv(ll n, ll mod)
{
    return binpow(n, mod - 2, mod);
}
struct SegTree
{
    vector<pair<ll, ll>> st;
    ll n;
    SegTree(ll sz = 0)
    {
        n = sz;
        st.resize(n << 1, make_pair(0, 0));
    }
    void set(ll i, ll v)
    {
        st[i + n] = make_pair(v, i);
    }
    void build()
    {
        for (ll i = n - 1; i >= 1; i--) st[i] = max(st[i << 1], st[i << 1 | 1]);
    }
    pair<ll, ll> query(ll l, ll r)
    {
        pair<ll, ll> ans = make_pair(-1, -1);
        for (l += n, r += n + 1; l < r; l >>= 1, r >>= 1)
        {
            if (l & 1) ans = max(ans, st[l++]);
            if (r & 1) ans = max(ans, st[--r]);
        }
        return ans;
    }
};
ll pref[2][N];
array<int, 2> gethash(ll l, ll r)
{
    if (l > r) return array<int, 2>{0, 0};
    array<int, 2> ans = {0, 0};
    for (ll i = 0; i < 2; i++)
        ans[i] = 1ll * (pref[i][r] - (l - 1 < 0 ? 0 : pref[i][l - 1]) + mod[i]) % mod[i] * invpw[i][l] % mod[i];
    return ans;
}
void solve()
{
    ll n, q;
    cin >> n >> q;
    string t[n];
    for (string &i : t) cin >> i;
    for (ll x = 0; x < 2; x++) pw[x][0] = invpw[x][0] = 1;
    for (ll x = 0; x < 2; x++)
    {
        ll invp = inv(p, mod[x]);
        for (ll i = 1; i < N; i++) pw[x][i] = 1ll * pw[x][i - 1] * p % mod[x];
        for (ll i = 1; i < N; i++) invpw[x][i] = 1ll * invpw[x][i - 1] * invp % mod[x];
    }
    vector<array<int, 2>> hs;
    hs.push_back({0, 0});
  	string s;
    cin >> s;
    for (string e : t)
    {
        array<int, 2> cur = {0, 0};
        for (ll j = 0; j < e.size(); j++)
        { 
            for (ll x = 0; x < 2; x++)
            cur[x] = (cur[x] + 1ll * (e[j] - 'a' + 1) * pw[x][j]) % mod[x];
            hs.push_back(cur);
        }
    }
    sort(hs.begin(), hs.end());
    for (ll x = 0; x < 2; x++)
    for (ll i = 0; i < s.size(); i++)
        pref[x][i] = ((i - 1 < 0 ? 0 : pref[x][i - 1]) + 1ll * (s[i] - 'a' + 1) * pw[x][i]) % mod[x];
    ll rig[s.size()];
    for (ll i = 0; i < s.size(); i++)
    {
        ll l = i, r = s.size() - 1, mid, pos;
        array<int, 2> p;
        rig[i] = i;
        while (l <= r)
        {
            mid = (l + r) >> 1;
            p = gethash(i, mid);
            pos = lower_bound(hs.begin(), hs.end(), p) - hs.begin();
            if (pos != hs.size() and hs[pos] == p) rig[i] = mid + 1, l = mid + 1;
            else r = mid - 1;
        }
    }
    SegTree st(s.size() + 1);
    for (ll i = 0; i < s.size(); i++) st.set(i, rig[i]);
    st.set(s.size(), s.size());
    st.build();
    for (ll i = 0; i < s.size(); i++) up[0][i] = rig[i] == i ? i : st.query(i, rig[i]).second;
    up[0][s.size()] = s.size();
    for (ll bit = 1; bit < lg; bit++)
        for (ll i = 0; i <= s.size(); i++) up[bit][i] = up[bit - 1][up[bit - 1][i]];
    while (q--)
    {
        ll l, r;
        cin >> l >> r;
        if (rig[l] >= r) cout << "1\n";
        else
        {
            ll ans = 1;
            for (ll bit = lg - 1; bit >= 0; bit--) if (rig[up[bit][l]] < r) ans += 1 << bit, l = up[bit][l];
            if (rig[up[0][l]] < r) ans = -1;
            else ans++;
            cout << ans << endl;
        }
    }
}
 
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll t = 1;
    // precomp();
    // cin >> t;
    for (ll cs = 1; cs <= t; cs++)
        solve();
    // cerr << "\nTime elapsed: " << clock() * 1000.0 / CLOCKS_PER_SEC << " ms\n";
}

Compilation message (stderr)

Main.cpp: In function 'void solve()':
Main.cpp:89:26: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |         for (ll j = 0; j < e.size(); j++)
      |                        ~~^~~~~~~~~~
Main.cpp:98:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   98 |     for (ll i = 0; i < s.size(); i++)
      |                    ~~^~~~~~~~~~
Main.cpp:101:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  101 |     for (ll i = 0; i < s.size(); i++)
      |                    ~~^~~~~~~~~~
Main.cpp:111:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |             if (pos != hs.size() and hs[pos] == p) rig[i] = mid + 1, l = mid + 1;
      |                 ~~~~^~~~~~~~~~~~
Main.cpp:116:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  116 |     for (ll i = 0; i < s.size(); i++) st.set(i, rig[i]);
      |                    ~~^~~~~~~~~~
Main.cpp:119:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  119 |     for (ll i = 0; i < s.size(); i++) up[0][i] = rig[i] == i ? i : st.query(i, rig[i]).second;
      |                    ~~^~~~~~~~~~
Main.cpp:122:26: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  122 |         for (ll i = 0; i <= s.size(); i++) up[bit][i] = up[bit - 1][up[bit - 1][i]];
      |                        ~~^~~~~~~~~~~

• Subtask 1: 25 / 25
• Subtask 2: 25 / 25
• Subtask 3: 50 / 50