Submission #959538

#	Time	Username	Problem	Language	Result	Execution time	Memory
959538		mannshah1211	Olympic Bus (JOI20_ho_t4)	C++17	0 / 100	2 ms	1628 KiB

ho_t4

/**
 *  author: hashman
 *  created: 
**/

#include <bits/stdc++.h>

using namespace std;

string to_string(string s) {
  return '"' + s + '"';
}

string to_string(const char* s) {
  return to_string((string) s);
}

string to_string(bool b) {
  return (b ? "true" : "false");
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
   if (!first) {
    res += ", ";
   }
   first = false;
   res += to_string(x);
  }
  res += "}";
  return res;
}

void debug_out() {
  cerr << endl;
}

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__);

constexpr int64_t inf = 1e18;

using P = pair<int64_t, int>;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  cin >> n >> m;
  vector<vector<pair<int, int>>> adj(n), radj(n);
  vector<int> u(m), v(m), c(n), d(m);
  for (int i = 0; i < m; i++) {
    cin >> u[i] >> v[i] >> c[i] >> d[i];
    u[i]--; v[i]--;
    adj[u[i]].push_back(make_pair(v[i], c[i]));
    radj[v[i]].push_back(make_pair(u[i], c[i]));
  }
  auto dijkstra = [&](int source) {
    vector<int64_t> dist(n, inf);
    dist[source] = 0;
    priority_queue<P, vector<P>, greater<P>> pq;
    pq.push(make_pair(0, source));
    while (!pq.empty()) {
      auto [expected, v] = pq.top();
      pq.pop();
      if (expected != dist[v]) {
        continue;
      }
      for (auto [now, wt] : adj[v]) {
        if (dist[now] > dist[v] + wt) {
          dist[now] = dist[v] + wt;
          pq.push(make_pair(dist[now], now));
        }
      }
    }
    return dist;
  };
  vector<int64_t> from_source = dijkstra(0);
  vector<int64_t> from_dest = dijkstra(n - 1);
  int64_t mn = inf;
  mn = min(mn, from_source[n - 1] + from_dest[0]);
  for (int i = 0; i < m; i++) {
    int64_t from = from_source[v[i]] + from_dest[u[i]], to = from_dest[v[i]] + from_source[u[i]];
    if (from > inf || to > inf) {
      continue;
    }
    mn = min(mn, from + d[i] + to);
  }
  cout << ((mn == inf) ? -1 : mn) << '\n';
}

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