oj.uz

Submission #290524

# Submission time Handle Problem Language Result Execution time Memory
290524 2020-09-03T23:41:29 Z VROOM_VARUN Valley (BOI19_valley) C++14
100 / 100
 417 ms 60720 KB 
/*
ID: varunra2
LANG: C++
TASK: valley
*/

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

#ifdef DEBUG
#include "lib/debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define debug_arr(...) \
  cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
#pragma GCC diagnostic ignored "-Wsign-compare"
//#pragma GCC diagnostic ignored "-Wunused-parameter"
//#pragma GCC diagnostic ignored "-Wunused-variable"
#else
#define debug(...) 42
#endif

#define EPS 1e-9
#define IN(A, B, C) assert(B <= A && A <= C)
#define INF (ll)1e15
#define MEM(a, b) memset(a, (b), sizeof(a))
#define MOD 1000000007
#define MP make_pair
#define PB push_back
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define x first
#define y second

const double PI = acos(-1.0);
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<ll> VI;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<string> VS;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define trav(a, x) for (auto& a : x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
#pragma GCC diagnostic ignored "-Wsign-compare"
// util functions

int n, s, e, q;
vector<VII> adj;
VI tin;
VI tout;
int curtime = 0;
VI magic;
VI dist;
VVI parmq;
VI cmin;
vector<bool> shop;
VII edg;
VVI lca;
const int segsize = 20;  // change this when submitting
// e is the root

void init() {
  adj.resize(n);
  tin.resize(n);
  tout.resize(n);
  magic.resize(n);
  dist.resize(n);
  parmq.resize(n);
  cmin.resize(n);
  shop.resize(n);
  edg.resize(n - 1);
  lca.resize(n);
  for (int i = 0; i < n; i++) {
    parmq[i].resize(segsize);
    lca[i].resize(segsize);
    cmin[i] = INF;
  }
}

bool isAnc(int u, int v) {
  if (u == -1) return true;
  if (v == -1) return false;
  return tin[u] <= tin[v] and tout[u] >= tout[v];
}

void dfs_lca(int u, int v) {
  lca[u][0] = v;
  tin[u] = ++curtime;
  for (int i = 1; i < segsize; i++) {
    int to = lca[u][i - 1];
    if (to == -1)
      lca[u][i] = -1;
    else
      lca[u][i] = lca[to][i - 1];
  }
  for (auto& x : adj[u]) {
    if (x.x == v) continue;
    dfs_lca(x.x, u);
  }
  tout[u] = ++curtime;
}

void dfs_dist(int u, int v) {
  for (auto& x : adj[u]) {
    if (x.x == v) continue;
    dist[x.x] = dist[u] + x.y;
    dfs_dist(x.x, u);
  }
}

void dfs_magic(int u, int v) {
  for (auto& x : adj[u]) {
    if (x.x == v) continue;
    dfs_magic(x.x, u);
    cmin[u] = min(cmin[u], cmin[x.x]);
  }
  if (shop[u]) cmin[u] = dist[u];
  magic[u] = -2 * dist[u] + cmin[u];
}

void dfs_build_parmq(int u, int v) {
  parmq[u][0] = magic[u];

  for (int i = 1; i < segsize; i++) {
    int to = lca[u][i - 1];
    if (to == -1)
      parmq[u][i] = parmq[u][i - 1];
    else
      parmq[u][i] = min(parmq[u][i - 1], parmq[to][i - 1]);
  }
  for (auto& x : adj[u]) {
    if (x.x == v) continue;
    dfs_build_parmq(x.x, u);
  }
}

ll qry(int u, int v) {
  ll ret = INF;
  for (int i = segsize - 1; i >= 0; i--) {
    if (!isAnc(lca[u][i], v)) {
      ret = min(ret, parmq[u][i]);
      u = lca[u][i];
    }
  }
  ret = min(ret, min(magic[v], magic[u]));
  return ret;
}

int main() {
  // #ifndef ONLINE_JUDGE
  //   freopen("valley.in", "r", stdin);
  //   freopen("valley.out", "w", stdout);
  // #endif
  cin.sync_with_stdio(0);
  cin.tie(0);

  cin >> n >> s >> q >> e;
  e--;

  init();

  for (int i = 0; i < n - 1; i++) {
    int u, v, w;
    cin >> u >> v >> w;
    u--;
    v--;
    adj[u].PB(MP(v, w));
    adj[v].PB(MP(u, w));
    edg[i] = MP(u, v);
  }

  for (int i = 0; i < s; i++) {
    int c;
    cin >> c;
    c--;
    shop[c] = true;
  }

  dfs_lca(e, -1);    // got in and out times of each node
  dfs_dist(e, -1);   // got distances
  dfs_magic(e, -1);  // made the magic array

  // now we need to calculate

  dfs_build_parmq(e, -1);

  // for(int i = 0; i < q; i++) {

  // }

  for (int i = 0; i < q; i++) {
    int ind, r;
    cin >> ind >> r;
    ind--;
    r--;
    int u, v;
    u = edg[ind].x;
    v = edg[ind].y;
    if (dist[u] < dist[v]) swap(u, v);
    if (!isAnc(u, r)) {
      cout << "escaped\n";
    } else {
      ll ret = dist[r] + qry(r, u);
      if (shop[r]) ret = 0;
      if (ret <= INF / 10 + 1ll)
        cout << ret << '\n';
      else
        cout << "oo" << '\n';
    }
  }

  return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 512 KB Output is correct
3 Correct 3 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct

Subtask #2
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 512 KB Output is correct
3 Correct 3 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct
5 Correct 2 ms 896 KB Output is correct
6 Correct 2 ms 896 KB Output is correct
7 Correct 2 ms 896 KB Output is correct
8 Correct 2 ms 896 KB Output is correct
9 Correct 2 ms 896 KB Output is correct
10 Correct 2 ms 896 KB Output is correct
11 Correct 2 ms 896 KB Output is correct
12 Correct 2 ms 896 KB Output is correct
13 Correct 2 ms 896 KB Output is correct
14 Correct 2 ms 896 KB Output is correct

Subtask #3
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 231 ms 57080 KB Output is correct
2 Correct 263 ms 56824 KB Output is correct
3 Correct 281 ms 57080 KB Output is correct
4 Correct 310 ms 58488 KB Output is correct
5 Correct 315 ms 58628 KB Output is correct
6 Correct 347 ms 60408 KB Output is correct

Subtask #4
41.0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 512 KB Output is correct
2 Correct 3 ms 512 KB Output is correct
3 Correct 3 ms 512 KB Output is correct
4 Correct 3 ms 512 KB Output is correct
5 Correct 2 ms 896 KB Output is correct
6 Correct 2 ms 896 KB Output is correct
7 Correct 2 ms 896 KB Output is correct
8 Correct 2 ms 896 KB Output is correct
9 Correct 2 ms 896 KB Output is correct
10 Correct 2 ms 896 KB Output is correct
11 Correct 2 ms 896 KB Output is correct
12 Correct 2 ms 896 KB Output is correct
13 Correct 2 ms 896 KB Output is correct
14 Correct 2 ms 896 KB Output is correct
15 Correct 231 ms 57080 KB Output is correct
16 Correct 263 ms 56824 KB Output is correct
17 Correct 281 ms 57080 KB Output is correct
18 Correct 310 ms 58488 KB Output is correct
19 Correct 315 ms 58628 KB Output is correct
20 Correct 347 ms 60408 KB Output is correct
21 Correct 247 ms 56568 KB Output is correct
22 Correct 278 ms 56312 KB Output is correct
23 Correct 306 ms 56568 KB Output is correct
24 Correct 368 ms 58232 KB Output is correct
25 Correct 398 ms 60720 KB Output is correct
26 Correct 246 ms 56572 KB Output is correct
27 Correct 273 ms 56312 KB Output is correct
28 Correct 298 ms 56568 KB Output is correct
29 Correct 363 ms 57720 KB Output is correct
30 Correct 417 ms 59128 KB Output is correct
31 Correct 240 ms 56568 KB Output is correct
32 Correct 276 ms 56392 KB Output is correct
33 Correct 305 ms 56696 KB Output is correct
34 Correct 371 ms 58232 KB Output is correct
35 Correct 398 ms 60720 KB Output is correct
36 Correct 347 ms 58232 KB Output is correct