Submission #958799

#	Time	Username	Problem	Language	Result	Execution time	Memory
958799		relex	Boat (APIO16_boat)	C++17	9 / 100	2 ms	476 KiB

boat

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
using namespace std;
using ll = long long;
using ld = long double;

struct custom_hash {
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};
gp_hash_table<ll, ll, custom_hash> app;
//constexpr ll MOD = 998244353;
constexpr ll MOD = 1e9 + 7;

constexpr ll INF = 3e18;



ll n, m, k, q, x, y, z, w, h, T;
string s, t;
double p;

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);

    ll n;
    cin >> n;

    pair<ll, ll> a[n];
    set<ll> s;
    for (ll i = 0; i < n; i++) {
        cin >> a[i].first >> a[i].second;
        s.insert(a[i].first); s.insert(a[i].second);
    }

    map<ll, ll> app;

    ll diff[2 * n + 10] = {};

    ll pr = 0;
    ll cur = 1;
    for (ll val : s) {
        app[val] = cur;
        diff[cur] = val - pr;
        pr = val;
        cur++;
    }
    for (ll i = 0; i < n; i++) {
        a[i].first = app[a[i].first]; a[i].second = app[a[i].second];
    }

    ll pref[cur] = {};
    fill(pref, pref + cur, 1);

    for (ll i = 0; i < n; i++) {
        ll dp[cur] = {};
        dp[a[i].first] = pref[a[i].first - 1];
        for (ll j = a[i].first + 1; j <= a[i].second; j++) {
            dp[j] = (pref[j - 1] * diff[j]) % MOD;
        }
        ll ad = 0;
        for (ll j = 1; j < cur; j++) {
            ad += dp[j];
            if (ad >= MOD) ad -= MOD;
            pref[j] += ad;
            if (pref[j] >= MOD) pref[j] -= MOD;
        }
    }

    ll ans = (pref[cur - 1] - 1 + MOD) % MOD;

    printf("%lld\n", ans);
}

• Subtask 1: 9 / 9
• Subtask 2: 0 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 42