Submission #536000

#	Time	Username	Problem	Language	Result	Execution time	Memory
536000		cig32	Long Mansion (JOI17_long_mansion)	C++17	10 / 100	3070 ms	146584 KiB

long_mansion

#include "bits/stdc++.h"
using namespace std;
const int MAXN = 5e5 + 10;
const int MOD = 1e9 + 7;
#define int long long
mt19937_64 rng((int)std::chrono::steady_clock::now().time_since_epoch().count());
int rnd(int x, int y) {
  int u = uniform_int_distribution<int>(x, y)(rng); return u;
}
int bm(int b, int p) { 
  if(p==0) return 1;
  int r = bm(b, p/2);
  if(p&1) return (((r*r) % MOD) * b) % MOD;
  return (r*r) % MOD;
}
int inv(int b) {
  return bm(b, MOD-2);
}
int f[MAXN];
int nCr(int n, int r) { 
  int ans = f[n]; ans *= inv(f[r]); ans %= MOD;
  ans *= inv(f[n-r]); ans %= MOD; return ans;
}

void precomp() { 
  f[0] = 1;
  for(int i=1; i<MAXN; i++) f[i] = (f[i-1] * i) % MOD;
}

vector<int> adj[MAXN];

int l[MAXN], r[MAXN], c[MAXN];
vector<int> List[MAXN];
unordered_map<int, int> contains[MAXN];
bool vis[MAXN];
int n;

stack<int> topo;

void dfs(int node) {
  vis[node] = 1;
  for(int x: adj[node]) {
    if(!vis[x]) {
      dfs(x);
    }
  }
  topo.push(node);
}

vector<int> adj2[MAXN], adj3[MAXN];

vector<vector<int> > compo;
vector<int> single;

void dfs2(int node) {
  vis[node] = 1;
  for(int x: adj2[node]) {
    if(!vis[x]) dfs2(x);
  }
  single.push_back(node);
}

int dsu[MAXN];
int set_of(int u) {
  if(dsu[u] == u) return u;
  return dsu[u] = set_of(dsu[u]);
}

void union_(int u, int v) {
  dsu[set_of(u)] = set_of(v);
}

void dfs3(int node) {
  vis[node] = 1;
  topo.push(node); // reverse topo order
  for(int x: adj3[node]) {
    if(!vis[x]) {
      dfs3(x);
    }
  }
}

vector<int> savior[MAXN]; // savior[i]: which nodes contain key i

void solve(int tc) {
  cin >> n;
  for(int i=1; i<=n; i++) {
    dsu[i] = i;
  }
  for(int i=1; i<n; i++) {
    cin >> c[i];
  }
  for(int i=1; i<=n; i++) {
    int x;
    cin >> x;
    for(int j=0; j<x; j++) {
      int y;
      cin >> y;
      List[i].push_back(y);
      savior[y].push_back(i);
      contains[i][y] = 1;
    }
  }
  for(int i=1; i<n; i++) {
    if(contains[i][c[i]]) adj[i].push_back(i + 1);
    if(contains[i+1][c[i]]) adj[i + 1].push_back(i);
  }
  for(int i=1; i<=n; i++) {
    if(!vis[i]) {
      dfs(i);
    }
  }
  for(int i=1; i<=n; i++) {
    vis[i] = 0;
    for(int j=0; j<adj[i].size(); j++) {
      adj2[adj[i][j]].push_back(i);
    }
  }
  while(topo.size()) {
    int t = topo.top(); topo.pop();
    if(!vis[t]) {
      single.clear();
      dfs2(t);
      compo.push_back(single);
    }
  }
  for(vector<int> v: compo) {
    for(int i=1; i<v.size(); i++) {
      if(set_of(v[i]) != set_of(v[i-1])) union_(v[i], v[i-1]);
    }
  }
  map<pair<int, int>, int> exists;
  for(int i=1; i<=n; i++) {
    for(int x: adj[i]) {
      int si = set_of(i), sx = set_of(x);
      if(si != sx && !exists[{si, sx}]) {
        exists[{si, sx}] = exists[{sx, si}] = 1;
        adj3[si].push_back(sx);
      }
    }
  }
  for(int i=1; i<=n; i++) vis[i] = 0;
  for(int i=1; i<=n; i++) {
    if(set_of(i) == i && !vis[i]) {
      dfs3(i);
    }
  }
  for(int i=1; i<=n; i++) l[i] = r[i] = i;
  while(topo.size()) {
    int t = topo.top(); topo.pop();
    for(int x: adj3[t]) {
      l[t] = min(l[t], l[x]);
      r[t] = max(r[t], r[x]);
    }
    while(1) {
      bool can = 0;
      if(l[t] > 1) {
        int key_id = c[l[t] - 1];
        if(savior[key_id].size()) {
          if(savior[key_id][savior[key_id].size() - 1] >= l[t]) {
            int lwb = *lower_bound(savior[key_id].begin(), savior[key_id].end(), l[t]);
            if(lwb <= r[t]) {
              l[t]--;
              can = 1;
            }
          }
        }
      }
      if(r[t] < n) {
        int key_id = c[r[t]];
        if(savior[key_id].size()) {
          if(savior[key_id][savior[key_id].size() - 1] >= l[t]) {
            int lwb = *lower_bound(savior[key_id].begin(), savior[key_id].end(), l[t]);
            if(lwb <= r[t]) {
              r[t]++;
              can = 1;
            }
          }
        }
      }
      if(!can) break;
    }
  }
  for(int i=1; i<=n; i++) {
    l[i] = l[set_of(i)], r[i] = r[set_of(i)];
  }
  int q;
  cin >> q;
  while(q--) {
    int x, y; cin >> x >> y;
    cout << (l[x] <= y && y <= r[x] ? "YES\n" : "NO\n");
  }
}
int32_t main(){
  precomp();
  ios::sync_with_stdio(0); cin.tie(0);
  int t = 1; //cin >> t;
  for(int i=1; i<=t; i++) solve(i);
} 

Compilation message (stderr)

long_mansion.cpp: In function 'void solve(long long int)':
long_mansion.cpp:115:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  115 |     for(int j=0; j<adj[i].size(); j++) {
      |                  ~^~~~~~~~~~~~~~
long_mansion.cpp:128:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  128 |     for(int i=1; i<v.size(); i++) {
      |                  ~^~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 0 / 15
• Subtask 4: 0 / 75