제출 #244920

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
244920		rama_pang	Olympic Bus (JOI20_ho_t4)	C++14	5 / 100	1090 ms	2932 KiB

ho_t4

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

using lint = long long;
const int MAXN = 205;
const int MAXM = 50005;

int N, M;
vector<int> adj[MAXN];
vector<int> radj[MAXN];
vector<array<int, 4>> edge;

int par[5][MAXN];
lint dist[5][MAXN];
int sptree[5][MAXM];

lint Dijkstra(int s, int k, vector<int> a[MAXN], int block = -1, int ru = -1, int rv = -1, int rc = -1, int target = -1) {
  for (int i = 0; i < MAXN; i++) {
    dist[k][i] = 1e18;
  }

  priority_queue<pair<lint, int>, vector<pair<lint, int>>, greater<pair<lint, int>>> pq;
  pq.emplace(0, s);
  auto dt = dist[k];
  auto pr = par[k];
  dt[s] = 0;
  pr[s] = 0;
  while (!pq.empty()) {
    int u = pq.top().second;
    lint d = pq.top().first;
    pq.pop();
    if (dt[u] != d) {
      continue;
    }
    if (u == target) {
      return d;
    }
    sptree[k][pr[u]] = 1;
    for (auto e : a[u]) if (e != block) {
      int v = edge[e][0] ^ edge[e][1] ^ u;
      if (dt[v] > dt[u] + edge[e][2]) {
        dt[v] = dt[u] + edge[e][2];
        pr[v] = e;
        pq.emplace(dt[v], v);
      }
    }
    if (u == ru) {
      int v = rv;
      if (dt[v] > dt[u] + rc) {
        dt[v] = dt[u] + rc;
        pr[v] = block;
        pq.emplace(dt[v], v);
      } 
    }
  }
  return 1e18;
}

int main() {
  ios::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);

  cin >> N >> M;
  for (int i = 0; i < M; i++) {
    int u, v, c, d;
    cin >> u >> v >> c >> d;
    edge.push_back({u, v, c, d});
    adj[u].emplace_back(i);
    radj[v].emplace_back(i);
  }

  Dijkstra(1, 0, adj); // 1 to N
  Dijkstra(N, 1, adj); // N to 1
  Dijkstra(1, 2, radj); // 1 to N, reverse
  Dijkstra(N, 3, radj); // N to 1, reverse
  // lint ans = dist[0][N] + dist[1][1];
  lint ans = Dijkstra(1, 4, adj, -1, -1, -1, -1, N) + Dijkstra(N, 4, adj, -1, -1, -1, -1, 1);
  for (int i = 0; i < M; i++) {
    int u, v, c, d;
    u = edge[i][0], v = edge[i][1], c = edge[i][2], d = edge[i][3];
    // if (sptree[0][i] == 0 && sptree[1][i] == 0) {
    //   ans = min(ans, d + min(dist[0][N], dist[0][v] + c + dist[2][u]) + 
    //                      min(dist[1][1], dist[1][v] + c + dist[3][u]));
    // } else {
      ans = min(ans, d + Dijkstra(1, 4, adj, i, v, u, c, N) + Dijkstra(N, 4, adj, i, v, u, c, 1));
    // }
  }
  if (ans > 1e17) {
    ans = -1;
  }
  cout << ans << "\n";
  return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 63