Submission #911269

#	Time	Username	Problem	Language	Result	Execution time	Memory
911269		green_gold_dog	Strange Device (APIO19_strange_device)	C++17	100 / 100	757 ms	100424 KiB

strange_device

//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx,avx2,sse,sse2,sse3,ssse3,sse4,abm,popcnt,mmx")
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef double db;
typedef long double ldb;
typedef complex<double> cd;

constexpr ll INF64 = 1'000'000'000'000'000'000, INF32 = 2'000'000'000, MOD = 1'000'000'007;
constexpr db PI = acos(-1);
constexpr bool IS_FILE = false, IS_TEST_CASES = false;

random_device rd;
mt19937 rnd32(rd());
mt19937_64 rnd64(rd());

template<typename T>
bool assign_max(T& a, T b) {
        if (b > a) {
                a = b;
                return true;
        }
        return false;
}

template<typename T>
bool assign_min(T& a, T b) {
        if (b < a) {
                a = b;
                return true;
        }
        return false;
}

template<typename T>
T square(T a) {
        return a * a;
}

template<>
struct std::hash<pair<ll, ll>> {
        ll operator() (pair<ll, ll> p) const {
                return ((__int128)p.first * MOD + p.second) % INF64;
        }
};

ll gcd(ll a, ll b) {
        return (min(a, b) == 0 ? max(a, b) : gcd(min(a, b), max(a, b) % min(a, b)));
}

void solve() {
        ll n, a, b;
        cin >> n >> a >> b;
        ll x = gcd(a, b + 1);
        ll mod = min((__int128)INF64, (__int128)a * b / x);
        map<ll, ll> add;
        for (ll i = 0; i < n; i++) {
                ll l, r;
                cin >> l >> r;
                r++;
                if (r - l >= mod) {
                        cout << mod << '\n';
                        return;
                }
                l %= mod;
                r %= mod;
                if (l <= r) {
                        add[l]++;
                        add[r]--;
                } else {
                        add[0]++;
                        add[mod]--;
                        add[l]++;
                        add[r]--;
                }
        }
        ll now = 0;
        ll ans = 0;
        ll lst = 0;
        for (auto[a, b] : add) {
                if (now) {
                        ans += a - lst;
                }
                lst = a;
                now += b;
        }
        cout << ans << '\n';
}

int main() {
        if (IS_FILE) {
                freopen("", "r", stdin);
                freopen("", "w", stdout);
        }
        ios_base::sync_with_stdio(false);
        cin.tie(0);
        cout.tie(0);
        ll t = 1;
        if (IS_TEST_CASES) {
                cin >> t;
        }
        for (ll i = 0; i < t; i++) {
                solve();
        }
}

Compilation message (stderr)

strange_device.cpp: In function 'int main()':
strange_device.cpp:95:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |                 freopen("", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~
strange_device.cpp:96:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |                 freopen("", "w", stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5
• Subtask 6: 20 / 20
• Subtask 7: 20 / 20
• Subtask 8: 30 / 30