Submission #734654

#	Time	Username	Problem	Language	Result	Execution time	Memory
734654		Sam_a17	Inside information (BOI21_servers)	C++17	5 / 100	3586 ms	83480 KiB

servers

#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
//#include "temp.cpp"
#include <cstdio>
using namespace std;
 
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif
 
#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt(x) __builtin_popcount(x)
 
#define pb push_back
#define popf pop_front
#define popb pop_back
 
void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(long double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
 
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(T v[],V n) {cerr << "["; for(int i = 0; i < n; i++) {print(v[i]); cerr << " "; } cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(deque <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
 
// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};
 
// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
  fastIO();
 
  if (str != "") {
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
  }
}
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 4e5 + 10, inf = 1e9 + 10, LOG = 21;
vector<pair<int, int>> adj[N];
long long ans[N], sz[N];
vector<int> qq[N], qx[N];
bool pp[N], used[N];
int n, q, compSize;

int up[N][LOG], in[N][LOG], dw[N][LOG];
int par[N], depths[N];

struct query {
  char type;
  int x, y;
};

vector<query> queries;

void dfsik(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];
    }


    in[i.first][0] = node;
    if(par[node] > i.second) {
      for(int j = 1; j < LOG; j++) {
        in[i.first][j] = in[in[i.first][j - 1]][j - 1];
      }
    }

    dw[i.first][0] = node;
    if(par[node] < i.second) {
      for(int j = 1; j < LOG; j++) {
        dw[i.first][j] = dw[dw[i.first][j - 1]][j - 1];
      }
    }

    par[i.first] = i.second;
    depths[i.first] = depths[node] + 1;
    dfsik(i.first, node);
  }

}

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

  if(depths[a] > depths[b]) {
    swap(a, b);
  }

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

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

int chk(int a, int b, int lst, int lim) {
  if(a == b) {
    return 1;
  }

  int ok = 0;
  for(auto i: adj[a]) {
    if(i.second > lim) continue;
    if(i.second > lst) {
      ok |= chk(i.first, b, i.second, lim);
    }
  }
  return ok;
}


bool check(int a, int b, int tt) {
  if(a == b) {
    return true;
  }

  int lc = lca(a, b), ok = 1;
  int first = depths[a] - depths[lc];
  int aa = a;

  for(int i = 0; i < LOG; i++) {
    if(first & (1 << i)) {
      if(!in[aa][i]) {
        ok = 0;
      } else {
        aa = in[aa][i];
      }
    }
  }

  int second = depths[b] - depths[lc];
  int bb = b;
  for(int i = 0; i < LOG; i++) {
    if(second & (1 << i)) {
      if(!dw[bb][i]) {
        ok = 0;
      } else {
        bb = dw[bb][i];
      }
    }
  }

  if(aa != bb) {
    return 0;
  }

  assert(ok == 1);

  if(lc == a || lc == b) {
    // if(lc == a && par[b] > tt) {
      // ok = 0;
    // } else if(lc == b) {

      // int na = go_up(a, first - 1);
      // if(par[na] > tt) {
        // ok = 0;
      // }
    // }
      return chk(a, b, -1, tt);
  } else {

    int na = go_up(a, first - 1);
    int nb = go_up(b, second - 1);

    if(par[na] > par[nb]) {
      ok = 0;
    }

    if(par[b] > tt) {
      ok = 0;
    }

    if(ok) {
      int pr = chk(a, b, -1, tt);
      return pr;
    }
  }

  return ok;
}


void dfs_sz(int node, int parent) {
  sz[node] = 1;
  compSize++;
  for(auto i: adj[node]) {
    if(i.first == parent || used[i.first]) continue;
    dfs_sz(i.first, node);
    sz[node] += sz[i.first];
  }
}

int centroid(int u, int parent) {
  for(auto i: adj[u]) {
    if(i.first == parent || used[i.first]) continue;
    if(sz[i.first] * 2 > compSize) {
      return centroid(i.first, u);
    }
  }
  return u;
}


// bit
struct fenwick {
  int size;
  vector<long long> tree; 

  void init(int size_) {
    tree.assign(size_ + 2, 0);
    size = size_;
  }

  void upd(int u, long long v) {
    while(u <= size) {
      tree[u] += v;
      u += u & (-u);
    }
  }

  long long qry(int u) {
    long long sum = 0;
    while(u > 0) {
      sum += tree[u];
      u -= u & (-u); // lsb
    }
    return sum;
  }

  long long sum(int l, int r) {
    if(l > r) {
      return 0;
    }
    return qry(r) - qry(l - 1);
  }

} ft_inc, ft_dec;

int get_centroid(int u) {
  compSize = 0;
  dfs_sz(u, 0);
  int center = centroid(u, 0);
  return center;
}

vector<int> which_dec;
vector<pair<int, int>> curr_inc, curr_dec;

bool rev = false;

void solve(int node, int parent, int incr, int decr, int lst, int st) {
  if(parent) {
    if(incr != -1) {
      curr_inc.push_back({st, node});
    }

    if(decr != -1) {
      curr_dec.push_back({lst, node});
      which_dec.push_back(lst);
    }
  }

  for(auto i: adj[node]) {
    if(i.first == parent || used[i.first]) continue;

    if(!parent) {
      solve(i.first, node, i.second, i.second, i.second, i.second);
    } else {
      int new_incr = -1, new_decr = -1;
      if(i.second < lst && incr != -1) {
        new_incr = i.second;
      }

      if(i.second > lst && decr != -1) {
        new_decr = i.second;
      }

      solve(i.first, node, new_incr, new_decr, i.second, st);
    }

    if(parent) continue;
    for(auto j: curr_inc) {
      for(auto k: qq[j.second]) {
        if(k < j.first) continue;
        ans[k - 1]++;
        ans[k - 1] += ft_dec.sum(j.first + 1, k);
      }
    }

    for(auto j: curr_dec) {
      ft_dec.upd(j.first, 1);
    }

    //
    curr_inc.clear();
    curr_dec.clear();
  }
}

void centroid_decomposition() {
  queue<int> q;
  q.push(1);

  while(!q.empty()) {
    auto u = q.front();
    q.pop();

    int center = get_centroid(u);
    solve(center, 0, -1, -1, -1, -1);

    for(auto k: qq[center]) {
      ans[k - 1] += ft_dec.sum(1, k - 1);
    }

    for(auto i: which_dec) {
      ft_dec.upd(i, -1);
    }
    which_dec.clear();

    used[center] = true;
    for(auto i: adj[center]) {
      if(used[i.first]) continue;
      q.push(i.first);
    }
  }
}

bool cmp(pair<int, int>& a, pair<int, int>& b) {
  return a.second > b.second;
}

void solve_() {
  cin >> n >> q;
  
  q += n - 1;

  ft_dec.init(N);

  for(int i = 0; i < q; i++) {
    char type; cin >> type;
    int x, y;
    if(type == 'S') {
      cin >> x >> y;
      adj[x].push_back({y, i + 1});
      adj[y].push_back({x, i + 1});
      queries.push_back({type, x, y});
    } else if(type == 'Q') {
      cin >> x >> y, pp[i] = true;
      qx[x].push_back(y);
      queries.push_back({type, x, y});
    } else {
      cin >> x, pp[i] = true;
      qq[x].push_back(i + 1);
      queries.push_back({type, x, -1});
    }
  }

  for(int i = 1; i <= n; i++) {
    sort(all(adj[i]), cmp);
  }

  centroid_decomposition();
  dfsik(1, 0);

  for(int i = 0; i < q; i++) {
    if(!pp[i]) continue;
    if(queries[i].type == 'Q') {
      if(check(queries[i].y, queries[i].x, i + 1)) {
        cout << "yes" << '\n';
      } else {
        cout << "no" << '\n';
      }
    } else {
      cout << ans[i] + 1 << '\n';
    }
  }
}
 
int main() {
  setIO();
 
  auto solve = [&](int test_case)-> void {
    while(test_case--) {
      solve_();
    }
  };
 
  int test_cases = 1;
  // cin >> test_cases;
  solve(test_cases);
 
  return 0;
} 

Compilation message (stderr)

servers.cpp: In function 'void setIO(std::string)':
servers.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
servers.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 2.5 / 2.5
• Subtask 2: 2.5 / 2.5
• Subtask 3: 0 / 2.5
• Subtask 4: 0 / 2.5
• Subtask 5: 0 / 5
• Subtask 6: 0 / 5
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 12.5
• Subtask 10: 0 / 12.5
• Subtask 11: 0 / 17.5
• Subtask 12: 0 / 17.5