Submission #954562

#	Time	Username	Problem	Language	Result	Execution time	Memory
954562		abczz	Commuter Pass (JOI18_commuter_pass)	C++14	24 / 100	2045 ms	39344 KiB

commuter_pass

#include <iostream>
#include <vector>
#include <array>
#include <algorithm>
#include <queue>
#define ll long long
#define ld long double

using namespace std;

priority_queue<array<ll, 2>, vector<array<ll, 2>>, greater<array<ll,2>>> pq;
vector <array<ll, 2>> adj[100000];
array <ll, 3> rt;
bool visited[100000];
queue <ll> Q;
array <ll, 2> dp[100000];
ll n, m, s, t, x, y, a, b, c, f, dist[3][100000], in[100000];

void dfs(ll u) {
  visited[u] = 1;
  for (auto [v, x] : adj[u]) {
    if (dist[0][v] + x == dist[0][u]) {
      ++in[v];
      if (!visited[v]) dfs(v);
    }
  }
}

int main() {
  cin >> n >> m >> s >> t >> x >> y;
  --s, --t, --x, --y;
  for (int i=0; i<m; ++i) {
    cin >> a >> b >> c;
    --a, --b;
    adj[a].push_back({b, c});
    adj[b].push_back({a, c});
  }
  for (int i=0; i<n; ++i) {
    for (int j=0; j<3; ++j) {
      dist[j][i] = 1e18;
    }
  }
  rt = {s, x, y};
  for (int i=0; i<3; ++i) {
    dist[i][rt[i]] = 0;
    pq.push({rt[i], 0});
    while (!pq.empty()) {
      auto [u, w] = pq.top();
      pq.pop();
      if (dist[i][u] != w) continue;
      for (auto [v, x] : adj[u]) {
        if (dist[i][v] > w+x) {
          dist[i][v] = w+x;
          pq.push({v, dist[i][v]});
        }
      }
    }
  }
  dfs(t);
  for (int i=0; i<n; ++i) {
    dp[i] = {dist[1][i], dist[2][i]};
  }
  f = dist[1][y];
  Q.push(t);
  while (!Q.empty()) {
    auto u = Q.front();
    Q.pop();
    f = min(f, dist[1][u] + dp[u][1]);
    f = min(f, dist[2][u] + dp[u][0]);
    for (auto [v, x] : adj[u]) {
      if (dist[0][v] + x == dist[0][u]) {
        --in[v];
        dp[v][0] = min(dp[v][0], dp[u][0]);
        dp[v][1] = min(dp[v][1], dp[u][1]);
        if (!in[v]) Q.push(v);
      }
    }
  }
  cout << f << '\n';
}

Compilation message (stderr)

commuter_pass.cpp: In function 'void dfs(long long int)':
commuter_pass.cpp:21:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   21 |   for (auto [v, x] : adj[u]) {
      |             ^
commuter_pass.cpp: In function 'int main()':
commuter_pass.cpp:48:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   48 |       auto [u, w] = pq.top();
      |            ^
commuter_pass.cpp:51:17: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   51 |       for (auto [v, x] : adj[u]) {
      |                 ^
commuter_pass.cpp:70:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   70 |     for (auto [v, x] : adj[u]) {
      |               ^

• Subtask 1: 0 / 16
• Subtask 2: 0 / 15
• Subtask 3: 24 / 24
• Subtask 4: 0 / 45