Submission #338518

#	Time	Username	Problem	Language	Result	Execution time	Memory
338518		boykut	Evacuation plan (IZhO18_plan)	C++14	35 / 100	635 ms	33512 KiB

plan

#include <bits/stdc++.h>

using namespace std;

// SNM
vector <int> par, siz, ans;
vector <set<int>> st;
void make_set(int n) {
   par = siz = vector<int> (1+n);
   for (int i = 0; i <= n; i++)
      par[i] = i, siz[i] = 1;
}
int find_set(int v) {
   if (v == par[v]) return v;
   return par[v] = find_set(par[v]);
}
void uni(int a, int b) {
   a = find_set(a);
   b = find_set(b);
   if (a != b) {
      if (siz[a] < siz[b])
         swap(a, b);
      siz[a] += siz[b];
      par[b] = a;
   }
}

signed main() {
   ios::sync_with_stdio(0);
   cin.tie(0);
   int n, m;
   cin >> n >> m;
   vector <pair<int,int>> g[1+n];
   vector <int> G[1+n];
   vector <int> d(1+n, INT_MAX), used(1+n, 0);
   st = vector <set<int>> (1+n);
   for (int i = 0; i < m; i++) {
      int u, v, cost;
      cin >> u >> v >> cost;
      g[u].push_back({v, cost}); G[u].push_back(v);
      g[v].push_back({u, cost}); G[v].push_back(u);
   }
   int k;
   cin >> k;
   vector <int> r(k);
   for (int i = 0; i < k; i++) {
      cin >> r[i];
   }
   priority_queue <pair<int,int>,vector<pair<int,int>>,greater<pair<int,int>>> qw;
   for (int i = 0; i < k; i++) {
      qw.push({0, r[i]});
      d[r[i]] = 0;
   }
   while (!qw.empty()) {
      int v = qw.top().second;
      qw.pop();
      if (used[v]) continue;
      used[v] = 1;
      for (pair<int,int> i : g[v]) {
         int to = i.first, len = i.second;
         if (d[v] + len < d[to]) {
            d[to] = d[v] + len;
            qw.push({d[to], to});
         }
      }
   }/*
   int q;
   cin >> q;
   ans = vector <int> (q);
   for (int i = 0; i < q; i++) {
      int s, t;
      cin >> s >> t;
      st[s].insert(i);
      st[t].insert(i);
   }
   make_set(n);
   vector <int> pos;
   for (int i = 1; i <= n; i++) {
      pos.push_back(i);
   }
   sort(pos.begin(), pos.end(), [&](int a, int b) {
      return d[a] > d[b];
   });
   used = vector <int> (1+n, 0);
   for (int v: pos) {
      used[v] = 1;
      for (int to: G[v]) {
         if (used[to]) {
            uni(v, to);
         }
      }
   }
   for (int i = 0; i < q; i++) {
      cout << ans[i] << '\n';
   }*/
   int q;
   cin >> q;
   if ((q <= 200 && n <= 15 && m <= 200)) {
      for (int i = 0; i < q; i++) {
         int s, t;
         cin >> s >> t;
         vector <int> d2(1+n, 0); d2[s] = d[s];
         priority_queue <pair<int,int>> qw;
         qw.push({d2[s], s});
         while (!qw.empty()) {
            int v = qw.top().second;
            qw.pop();
            for (int to : G[v]){
               if (d2[to] < d2[v]){
                  d2[to] = min(d[to], d2[v]);
                  qw.push({d2[to], to});
               }
            }
         }
         cout << d2[t] << '\n';
      }
   } else {
      for (int i = 0; i < q; i++) {
         int s, t;
         cin >> s >> t;
         cout << min(d[s], d[t]) << '\n';
      }
   }
   return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 13 / 13
• Subtask 3: 12 / 12
• Subtask 4: 0 / 19
• Subtask 5: 0 / 46