Submission #862978

#	Time	Username	Problem	Language	Result	Execution time	Memory
862978		Erfan1386Y	Valley (BOI19_valley)	C++14	59 / 100	3074 ms	18896 KiB

valley

#include <bits/stdc++.h>
#define file_io freopen("input.txt", "r", stdin);freopen("output.txt", "w", stdout);
#define fast_io ios::sync_with_stdio(false);cin.tie(0);
#define what(x) cerr << #x << " is " << x << endl;
#define kill(x) {cout << x << '\n'; continue;}
#define all(x) (x).begin(), (x).end()
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pb push_back
#define ll long long
#define F first
#define S second
const ll inf = 1e14, mod = 1e9 + 7, delta = 1e8, SQ = 800; //998244353

using namespace std;

const ll N = 1e5 + 10, LG = 20;

#define piii array<int, 3>
int cnt, st[N], ft[N];
vector<piii> adj[N];
vector<int> maghaze, t;
pll par[N], d[N], dd[N], edges[N];
bitset<N> mark;
ll dis[N];

void dfs (int v, int p, int e) {
  t.pb(v);
  st[v] = cnt++;
  par[v] = pii(p, e);
  for (auto u: adj[v])
    if (u[0] - p) dfs(u[0], v, u[2]);
  ft[v] = cnt;
}

void dfs (int v, int e) {
  mark[v] = true;
  for (auto u: adj[v])
    if (u[2] != e && !mark[u[0]])
      dfs(u[0], e);
}

bool cmp (piii a, piii b){
  return a[1] < b[1];
}

int32_t main() {
  fast_io;
  int n, s, q, e;
  cin >> n >> s >> q >> e;
  for (int i = 1; i < n; i++) {
    int u, v, w;
    cin >> u >> v >> w;
    adj[u].pb({v, w, i});
    adj[v].pb({u, w, i});
    edges[i] = pii(u, v);
  }
  for (int i = 1; i <= s; i++) {
    int v;
    cin >> v;
    maghaze.pb(v);
  }
  if (s == n) {
    dfs(1, -1, -1);
    for (int j = 1; j <= q; j++) {
      int ii, r;
      cin >> ii >> r;
      int u = edges[ii].F, v = edges[ii].S;
      if (v == par[u].F) swap(u, v);
      bool b = (st[e] >= st[v] && st[e] < ft[v]), bb = (st[r] >= st[v] && st[r] < ft[v]);
      if (b && bb) cout << "escaped\n";
      else if (b || bb) cout << "0\n";
      else cout << "escaped\n";
    }
  }
  else {
    while (q--) {
      int ii, r;
      cin >> ii >> r;
      mark.reset();
      dfs(r, ii);
      if (mark[e]) kill("escaped");
      mark.reset();
      priority_queue<pii, vector<pii>, greater<pii>> q;
      q.push(pii(0, r));
      memset(dis, 63, sizeof dis);
      dis[r] = 0;
      while (q.size()) {
        int v = q.top().S;
        q.pop();
        if (mark[v]) continue;
        mark[v] = true;
        for (auto u: adj[v]) {
          if (u[2] != ii && dis[u[0]] > dis[v] + u[1]) {
            dis[u[0]] = dis[v] + u[1];
            q.push(pii(dis[u[0]], u[0]));
          }
        }
      }
      ll mn = inf;
      for (auto u: maghaze) mn = min(mn, dis[u]);
      if (mn == inf) cout << "oo\n";
      else cout << mn << '\n';
    }
  }
  return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 27 / 27
• Subtask 3: 23 / 23
• Subtask 4: 0 / 41