Submission #1267210

#	Time	Username	Problem	Language	Result	Execution time	Memory
1267210		quangminh412	Treatment Project (JOI20_treatment)	C++17	0 / 100	1 ms	576 KiB

treatment

/*
  Ben Watson

  Quang Minh MasterDDDDD
*/

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

#define ll long long

const string name = "test";

void solve();
signed main()
{
    if (fopen((name + ".inp").c_str(), "r"))
    {
        freopen((name + ".inp").c_str(), "r", stdin);
        freopen((name + ".ans").c_str(), "w", stdout);
    }
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    solve();

    return 0;
}

// main program
const ll oo = 0x3f3f3f3f3f3f3f3f;
const int maxm = 5001;

int t[maxm], l[maxm], r[maxm], c[maxm];
vector<int> S, T, adj[maxm];
int n, m;

void build(int i, int j)
{
    if (l[i] > l[j]) swap(i, j);
    if (r[i] < l[j] - 1) return;
    int diff = abs(t[i] - t[j]);
    int l1 = l[i], r1 = r[i], l2 = l[j], r2 = r[j];
    if (t[i] < t[j])
        r1 -= diff;
    else
    {
        l2 += diff;
        if (l2 > r2)
            return;
    }
//    if (i == 5 && j == 3)
//        cout << l1 << ' ' << r1 << ' ' << l2 << ' ' << r2 << '\n';
    if (r1 < l2 - 1) return;
//    cout << i << ' ' << j << '\n';
    adj[i].push_back(j);
//    cout << i << ' ' << j << '\n';
}

vector<ll> Dijsktra(int s)
{
    vector<ll> dist(m + 1, oo);
    priority_queue<pair<ll, int>, vector<pair<ll, int>>, greater<pair<ll, int>>> pq;
    pq.push({dist[s] = c[s], s});
    while (!pq.empty())
    {
        int u = pq.top().second;
        ll w = pq.top().first;
        pq.pop();

        if (dist[u] != w)
            continue;

        for (int v : adj[u])
            if (dist[v] > dist[u] + c[v])
                pq.push({dist[v] = dist[u] + c[v], v});
    }
    return dist;
}

void solve()
{
    cin >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        cin >> t[i] >> l[i] >> r[i] >> c[i];
        if (l[i] == 1)
            S.push_back(i);
        if (r[i] == n)
            T.push_back(i);
    }

    for (int i = 1; i <= m; i++)
        for (int j = i + 1; j <= m; j++)
        {
            build(i, j);
            build(j, i);
        }

    ll res = oo;
    for (int s : S)
    {
        vector<ll> dist = Dijsktra(s);
        for (int t : T)
            res = min(res, dist[t]);
//        if (s == 5)
//            for (int t : T)
//            cout << t << ' ' << dist[t] << '\n';
    }

    cout << (res == oo ? -1 : res) << '\n';
}

Compilation message (stderr)

treatment.cpp: In function 'int main()':
treatment.cpp:19:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |         freopen((name + ".inp").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
treatment.cpp:20:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |         freopen((name + ".ans").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 5
• Subtask 3: 0 / 30
• Subtask 4: 0 / 61