Submission #284620

#	Time	Username	Problem	Language	Result	Execution time	Memory
284620		AaronNaidu	Strange Device (APIO19_strange_device)	C++14	100 / 100	983 ms	68520 KiB

strange_device

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;

ll n, a, b, l, r, per;
set<pair<ll, ll> > segments, newSegments;

ll gcd(ll x, ll y) {
    if (y == 0)
    {
        return x;
    }
    return gcd(y, x % y);
}

void addSegment(ll sta, ll fin) {
    auto startPos = segments.upper_bound({sta, per});
    if (startPos == segments.begin())
    {
        for (auto i = segments.begin(); i != segments.end(); )
        {
            if (i->first <= fin)
            {
                fin = max(fin, i->second);
                segments.erase(i++);
            }
            else
            {
                break;
            }
        }
        segments.insert({sta, fin});
        return;
    }
    startPos--;
    if (startPos->second >= sta)
    {
        sta = min(sta, startPos->first);
        fin = max(fin, startPos->second);
        segments.erase(startPos++);
    }
    else
    {
        startPos++;
    }
      
    for (auto i = startPos; i != segments.end(); )
    {
        if (i->first <= fin)
        {
            fin = max(fin, i->second);
            segments.erase(i++);
        }
        else
        {
            break;
        }
    }
    segments.insert({sta, fin});     
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n >> a >> b;
    per = gcd(a, b+1);
    ld A = a;
    ld B = b;
    ld t = A/(1000000000000000007) * B;
    if (t > per)
    {
        per = 1000000000000000007;
    }
    else
    {
        per = round(A/per * B);
    }
    cin >> l >> r;
    if (r-l+1 >= per)
    {
        cout << per << "\n";
        return 0;
    }
    l = l%per;
    r = r%per;
    if(l <= r) {
        segments.insert({l, r});
    }
    else
    {
        segments.insert({0, r});
        segments.insert({l, per-1});
    }
    for (int i = 1; i < n; i++)
    {
        cin >> l >> r;
        if (r-l+1 >= per)
        {
        cout << per << "\n";
        return 0;
        }
        l = l%per;
        r = r%per;
        if (l <= r)
        {
            addSegment(l, r);
        }
        else
        {
            addSegment(0, r);
            addSegment(l, per-1);
        }
    }
    ll runningTotal = 0;
    for (auto i : segments)
    {
        runningTotal += i.second - i.first + 1;
    }
    cout << runningTotal << "\n";
}

• 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