Submission #1015236

#	Time	Username	Problem	Language	Result	Execution time	Memory
1015236		aufan	Strange Device (APIO19_strange_device)	C++17	100 / 100	669 ms	100344 KiB

strange_device

#include <bits/stdc++.h>
#define int long long
#define fi first
#define se second

using namespace std;

const int INFF = 2e18;

int32_t main()
{
        ios_base::sync_with_stdio(false);
        cin.tie(NULL);
        
        int n, a, b;
        cin >> n >> a >> b;

        int len = lcm(a, b + 1) / (b + 1) * b;

        set<pair<int, int>> seg;
        
        auto insert = [&](int l, int r) {
                auto it = seg.lower_bound({l, 0});
                if (!seg.empty() && it != seg.begin()) --it;

                int mnl = l, mxr = r;
                vector<pair<int, int>> del;

                for (; it != seg.end(); it++) {
                        if (it->fi > r) break;

                        if (it->fi < l && it->se >= l) {
                                del.push_back(*it);
                                mnl = min(mnl, it->fi);
                                mxr = max(mxr, it->se);
                        }

                        if (it->fi >= l && it->fi <= r) {
                                del.push_back(*it);
                                mnl = min(mnl, it->fi);
                                mxr = max(mxr, it->se);
                        }
                }

                for (auto p : del) seg.erase(p);

                seg.insert({mnl, mxr});
        };

        for (int i = 0; i < n; i++) {
                int l, r;
                cin >> l >> r;

                if (a <= INFF / b && r - l + 1 >= len) {
                        cout << len << '\n';
                        return 0;
                }
                
                if (a <= INFF / b) {
                        l %= len;
                        r %= len;
                }

                if (l <= r) {
                        insert(l, r);
                } else {
                        assert(a <= INFF / b);

                        insert(l, len - 1);
                        insert(0, r);
                }
        }
        
        int ans = 0;
        for (auto [l, r] : seg) ans += r - l + 1;

        cout << ans << '\n';

        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