Submission #1309717

#	Time	Username	Problem	Language	Result	Execution time	Memory
1309717		Euclid73	Palembang Bridges (APIO15_bridge)	C++20	100 / 100	68 ms	6108 KiB

bridge

#include <bits/stdc++.h>
using namespace std;

#define ll long long

bool cmp(pair<ll, ll> a, pair<ll, ll> b)
{
    return a.first + a.second < b.first + b.second;
}

priority_queue<ll> lpq;
priority_queue<ll, vector<ll>, greater<ll>> rpq;
ll lsum, rsum;

void insert(ll x) {
    ll median = (lpq.size() ? lpq.top() : 1000000001);
    if (x <= median)
    {
        lpq.push(x);
        lsum += x;
    }
    else
    {
        rpq.push(x);
        rsum += x;
    }
    if (rpq.size() + 1 < lpq.size())
    {
        ll nxt = lpq.top();
        lpq.pop();
        rpq.push(nxt);
        lsum -= nxt;
        rsum += nxt;
    }
    else if (lpq.size() < rpq.size())
    {
        ll nxt = rpq.top();
        rpq.pop();
        lpq.push(nxt);
        rsum -= nxt;
        lsum += nxt;
    }
}

ll pref[100001];

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    ll k, n;
    ll same_side = 0;
    vector<pair<ll, ll>> v = {{0, 0}};
    cin >> k >> n;
    for (int i = 0; i < n; i++)
    {
        char a, b;
        ll x, y;
        cin >> a >> x >> b >> y;
        if (a == b)
        {
            same_side += abs(x - y);
        }
        else
        {
            v.push_back({x, y});
        }
    }
    sort(v.begin(), v.end(), cmp);
    n = v.size() - 1;
    same_side += n;
    lsum = rsum = 0;
    for (int i = 1; i <= n; i++)
    {
        insert(v[i].first);
        insert(v[i].second);
        pref[i] = rsum - lsum;
    }
    ll ans = pref[n];
    
    if (k == 2)
    {
        while (lpq.size())
            lpq.pop();
        while (rpq.size())
            rpq.pop();
        lsum = rsum = 0;
        for (int i = n; i >= 1; i--)
        {
            insert(v[i].first);
            insert(v[i].second);
            ans = min(ans, rsum - lsum + pref[i - 1]);
        }
    }
    cout << same_side + ans << "\n";
}

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 9 / 9
• Subtask 4: 32 / 32
• Subtask 5: 37 / 37