Submission #577312

#	Time	Username	Problem	Language	Result	Execution time	Memory
577312		Sam_a17	Factories (JOI14_factories)	C++14	0 / 100	32 ms	6868 KiB

factories

#include <bits/stdc++.h>
#include "factories.h"
using namespace std;
const int maxN = 2e5 + 10, LOG = 22;
vector<pair<int, long long>> adj[maxN];
int sz[maxN], up[maxN][LOG], depth[maxN], compSize, p[maxN];
long long dist[maxN], sub[maxN];
bool used[maxN];

void dfs_lca(int node, int parent) {
  for(auto i: adj[node]) {
    if(i.first == parent) continue;
    up[i.first][0] = node;
    for(int j = 1; j < LOG; j++) {
      up[i.first][j] = up[up[i.first][j - 1]][j - 1];
    }
    dist[i.first] = dist[node] + i.second;
    depth[i.first] = depth[node] + 1;
    dfs_lca(i.first, node);
  }
}

int lca(int a, int b) {
  if(a == b) {
    return a;
  }

  if(depth[a] < depth[b]) {
    swap(a, b);
  }

  int delta = depth[a] - depth[b];

  for(int i = 0; i < LOG; i++) {
    if(delta & (1 << i)) {
      a = up[a][i];
    }
  }

  if(a == b) {
    return a;
  }

  for(int i = LOG - 1; i >= 0; i--) {
    if(up[a][i] != up[b][i]) {
      a = up[a][i], b = up[b][i];
    }
  }

  return up[a][0];
}

long long distance(int a, int b) {
  return dist[a] + dist[b] - 2 * dist[lca(a, b)];
}

int dfs_sz(int node, int parent) {
  sz[node] = 1, compSize++;
  for(auto i: adj[node]) {
    if(i.first == parent || used[i.first]) continue;
    sz[node] += dfs_sz(i.first, node);
  }
  return sz[node];
}
 
int get_centroid(int node, int parent) {
  for(auto i: adj[node]) {
    if(i.first == parent || used[i.first]) continue;
    if(2 * sz[i.first] > compSize) {
      return get_centroid(i.first, node);
    }
  }
  return node;
}
 
int find_centroid(int node, int parent) {
  compSize = 0;
  dfs_sz(node, 0);
  int centroid = get_centroid(node, 0);
  return centroid;
}
 
void centroid_decomposition() {
  queue<pair<int, int>> q;
  q.push({1, 0});
  dfs_lca(1, 0);
 
  for(int i = 0; i < maxN; i++) {
    sub[i] = 1e15;
  }

  while(!q.empty()) {
    auto u = q.front();
    q.pop();
 
    int centroid = find_centroid(u.first, 0);
 
    if(u.second) {
      p[centroid] = u.second;
    }
 
    used[centroid] = true;
    for(auto i: adj[centroid]) {
      if(used[i.first]) continue;
      q.push({i.first, centroid});
    }
 
  }
}

void Init(int N, int A[], int B[], int D[]) {
  for(int i = 0; i < N; i++) {
    int a = A[i], b = B[i], c = D[i];
    a++, b++;
    adj[a].push_back({b, c});
    adj[b].push_back({a, c}); 
  }

  centroid_decomposition();
}


set<int> need_to_erase;

void upd(int node) {
  int curr = node;
  while(curr) {
    sub[curr] = min(sub[curr], distance(node, curr));
    need_to_erase.insert(curr);
    curr = p[curr];
  }
}

long long qry(int node) {
  long long answ = sub[node], curr = node;
  while(curr) {
    answ = min(answ, sub[node] + distance(node, curr));
    curr = p[curr];
  }
  return answ;
}

long long Query(int S, int X[], int T, int Y[]) {
  long long answ = 1e15;
  if(S < T) {
    for(int i = 0; i < S; i++) {
      upd(X[i] + 1);
    }

    for(int i = 0; i < T; i++) {
      answ = min(answ, qry(Y[i] + 1));
    }
  } else {
    for(int i = 0; i < T; i++) {
      upd(Y[i] + 1);
    }

    for(int i = 0; i < S; i++) {
      answ = min(answ, qry(X[i] + 1));
    }
  }

  for(auto i: need_to_erase) {
    sub[i] = 1e15;
  } need_to_erase.clear();

  return answ;
}

• Subtask 1: 0 / 15
• Subtask 2: 0 / 18
• Subtask 3: 0 / 67