Submission #485563

#	Time	Username	Problem	Language	Result	Execution time	Memory
485563		dxz05	Strange Device (APIO19_strange_device)	C++14	100 / 100	442 ms	53208 KiB

strange_device

#pragma GCC optimize("Ofast,O2,O3,unroll-loops")
#pragma GCC target("avx2")

#include <bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << "[" << H << "]";
    debug_out(T...);
}

#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SZ(s) ((int)s.size())
#define all(x) (x).begin(), (x).end()
#define lla(x) (x).rbegin(), (x).rend()

clock_t startTime;

double getCurrentTime() {
    return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}

#define MP make_pair

typedef long long ll;
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
const double eps = 0.000001;
const int MOD = 1e9 + 7;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 1e6 + 3e2;
const int M = 2222;

void solve(int TC) {
    int n; ll a, b;
    cin >> n >> a >> b;

    ll x;
    if (double(a) / __gcd(a, b + 1) * b > 3e18){
        x = 4e18;
    } else x = a / __gcd(a, b + 1) * b;

    vector<pair<ll, ll>> segments;
    for (int i = 1; i <= n; i++){
        ll l, r;
        cin >> l >> r;

        if (r - l + 1 >= x){
            cout << x << endl;
            return;
        }

        l %= x, r %= x;

        if (l > r){
            segments.emplace_back(l, x - 1);
            segments.emplace_back(0, r);
        } else segments.emplace_back(l, r);

    }

    sort(all(segments));

    ll ans = 0;
    n = segments.size();
    for (int i = 0; i < n;){
        ll l = segments[i].first, r = segments[i].second;
        int j = i;
        while (j < n && segments[j].first <= r){
            r = max(r, segments[j].second);
            j++;
        }

        ans += r - l + 1;

        i = j;
    }

    cout << ans;

}

int main() {
    startTime = clock();
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

#ifdef dddxxz
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    int TC = 1;
//    cin >> TC;

    for (int test = 1; test <= TC; test++) {
        //debug(test);
        //cout << "Case #" << test << ": ";
        solve(test);
    }

    cerr << endl << "Time: " << int(getCurrentTime() * 1000) << " ms" << endl;

    return 0;
}

• 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