Submission #563618

#	Time	Username	Problem	Language	Result	Execution time	Memory
563618		Ooops_sorry	Strange Device (APIO19_strange_device)	C++14	100 / 100	665 ms	117536 KiB

strange_device

#include<bits/stdc++.h>

using namespace std;

#define pb push_back
#define ld long double
#define ll long long

mt19937 rnd(51);

ll gcd(ll a, ll b) {
    if (b == 0) {
        return a;
    } else {
        return gcd(b, a % b);
    }
}

__int128 lcm(ll a, ll b) {
    return (__int128)a * b / gcd(a, b);
}

ll solve(ll n, ll a, ll b, vector<ll> l, vector<ll> r) {
    ll ans = 0, need;
    bool was = 0, sum = 0;
    ll k = lcm(a, b + 1) / (__int128)(b + 1);
    if (log2(k) + log2(b) > log2(1e18) + 1) {
        sum = 1;
    } else {
        need = k * b;
    }
    vector<pair<ll, ll>> seg, u;
    for (int i = 0; i < n; i++) {
        if (sum) {
            ans += r[i] - l[i] + 1;
        } else {
            if (r[i] - l[i] + 1 >= need) {
                was = 1;
            } else {
                ll l1 = l[i] % (need), r1 = r[i] % (need);
                if (l1 <= r1) {
                    seg.pb({l1, r1});
                } else {
                    seg.pb({l1, need - 1});
                    seg.pb({0, r1});
                }
            }
        }
    }
    if (was) {
        return need;
    }
    if (sum) {
        return ans;
    } else {
        for (auto to : seg) {
            u.pb({to.first, 1});
            u.pb({to.second + 1, -1});
        }
        sort(u.begin(), u.end());
        ll bal = 0, last = -1;
        for (auto to : u) {
            if (bal > 0) {
                ans += to.first - last;
            }
            bal += to.second;
            last = to.first;
        }
        return ans;
    }
}

signed main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif // LCOAL
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll n, a, b;
    cin >> n >> a >> b;
    vector<ll> l(n), r(n);
    for (int i = 0; i < n; i++) {
        cin >> l[i] >> r[i];
    }
    cout << solve(n, a, b, l, r) << 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