Submission #1004842

#	Time	Username	Problem	Language	Result	Execution time	Memory
1004842		aykhn	Inside information (BOI21_servers)	C++17	2.50 / 100	70 ms	51140 KiB

servers

#include <bits/stdc++.h>
 
using namespace std;
 
#define int long long
#define inf 0x3F3F3F3F3F3F3F3F
 
const int MXN = 12e4 + 5;
const int mod = 1e9 + 7;
const int LOG = 20;
 
struct BIT
{
  int n;
  vector<int> ft;
  void init(int N)
  {
    n = N + 5;
    ft.assign(n + 5, 0);
  }
  void add(int pos, int val)
  {
    for (pos = pos + 1; pos <= n; pos += pos & -pos) ft[pos] += val;
  }
  int get(int pos, int res = 0)
  {
    for (pos = pos + 1; pos > 0; pos -= pos & -pos) res += ft[pos];
    return res;
  }
};
 
int n, m;
vector<array<int, 2>> adj[MXN];
int used[MXN], sz[MXN];
BIT ft[MXN];
int cent[LOG][MXN], w[LOG][MXN];
int ic[LOG][MXN], dc[LOG][MXN];
vector<array<int, 3>> ed;
array<int, 2> rep[LOG][MXN];
int tim;
 
void getsize(int a, int p)
{
  sz[a] = 1;
  for (array<int, 2> &v : adj[a])
  {
    if (used[v[0]] || v[0] == p) continue;
    getsize(v[0], a);
    sz[a] += sz[v[0]];
  }
}
int findcent(int a, int p, int &curn)
{
  for (array<int, 2> &v : adj[a])
  {
    if (used[v[0]] || v[0] == p) continue;
    if (sz[v[0]] > curn / 2) return findcent(v[0], a, curn); 
  }
  return a;
}
void dfs(int a, int p, int &lvl, int &cc, array<int, 2> &as)
{
  rep[lvl][a] = as;
  cent[lvl][a] = cc;
  for (array<int, 2> &v : adj[a])
  {
    if (used[v[0]] || v[0] == p) continue;
    w[lvl][v[0]] = v[1];
    dfs(v[0], a, lvl, cc, as);
  }
}
void maincent(int a, int lvl)
{
  getsize(a, a);
  int c = findcent(a, a, sz[a]);
  ic[lvl][c] = dc[lvl][c] = 1;
  used[c] = 1;
  cent[lvl][c] = c;
  for (array<int, 2> &v : adj[c])
  {
    if (used[v[0]]) continue;
    w[lvl][v[0]] = v[1];
    dfs(v[0], c, lvl, c, v);
  }
  for (array<int, 2> &v : adj[c])
  {
    if (used[v[0]]) continue;
    maincent(v[0], lvl + 1);
  }
}
 
int nw = 0;
 
void upd(int a, int p, int &lvl)
{
  if (!ic[lvl][a] && !dc[lvl][a]) return;
  nw += ic[lvl][a];
  for (array<int, 2> &v : adj[a])
  {
    if (cent[lvl][v[0]] != cent[lvl][a] || v[0] == p) continue;
    if (v[1] > tim) continue;
    ic[lvl][v[0]] = w[lvl][a] < v[1];
    dc[lvl][v[0]] = w[lvl][a] > v[1];
    upd(v[0], a, lvl);
  }
}
 
int getind(int c, int ind)
{
  int l = 0, r = (int)adj[c].size() - 1;
  while (l < r)
  {
    int mid = (l + r) >> 1;
    if (adj[c][mid][1] >= ind) r = mid;
    else l = mid + 1;
  }
  return l;
}
 
void add(int c, int ind, int val)
{
  ind = getind(c, ind);
  ft[c].add(ind, val);
}

int ans;
void calcans(int a, int p, int w)
{
  ans++;
  for (array<int, 2> &v : adj[a])
  {
    if (v[0] == p || v[1] < w) continue;
    calcans(v[0], a, v[1]);
  }
}
signed main()
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> m;
  ed.resize(n + m - 1);
  for (array<int, 3> &e : ed)
  {
    char ch;
    cin >> ch >> e[1];
    if (ch == 'S')  cin >> e[2], e[0] = 0;
    else if (ch == 'Q') cin >> e[2], e[0] = 1;
    else e[0] = 2;
  }
  for (int i = 0; i < ed.size(); i++)
  {
    array<int, 3> &e = ed[i];
    if (!e[0]) adj[e[1]].push_back({e[2], i}), adj[e[2]].push_back({e[1], i});
  }
  for (int i = 1; i <= n; i++)
  {
    ft[i].init(adj[i].size());
  }
  maincent(1, 0);
  for (tim = 0; tim < ed.size(); tim++)
  {
    array<int, 3> &e = ed[tim];
    int x = e[1], y = e[2];
    if (!e[0])
    {
      for (int i = 0; i < LOG; i++)
      {
        if (!cent[i][x] || !cent[i][y] || cent[i][x] != cent[i][y]) break;
        nw = 0;
        if (cent[i][x] == x) 
        {
          ic[i][y] = 1;
          dc[i][y] = 1;
          upd(y, x, i);
          if (nw) add(cent[i][y], rep[i][y][1], nw);
        }
        else if (cent[i][x] == y) 
        {
          ic[i][x] = 1;
          dc[i][x] = 1;
          upd(x, y, i);
          if (nw) add(cent[i][x], rep[i][x][1], nw);
        }
        else
        {
          int fx = 0, fy = 0;
          if (ic[i][x] && w[i][x] < w[i][y]) ic[i][y] = 1, fy = 1;
          else if (ic[i][y] && w[i][y] < w[i][x]) ic[i][x] = 1, fx = 1;
          if (dc[i][x] && w[i][x] > w[i][y]) dc[i][y] = 1, fy = 1;
          else if (dc[i][y] && w[i][y] > w[i][x]) dc[i][x] = 1, fx = 1;
          if (fx) 
          {
            upd(x, y, i);
            if (nw) add(cent[i][x], rep[i][x][1], nw);
            nw = 0;
          }
          if (fy) 
          {
            upd(y, x, i);
            if (nw) add(cent[i][y], rep[i][y][1], nw);
            nw = 0;
          }
        }
      }
    }
    else if (e[0] == 1)
    {
      int lg = -1;
      for (int i = 0; i < LOG; i++)
      {
        if (!cent[i][x] || !cent[i][y] || cent[i][x] != cent[i][y]) 
        {
          lg = i - 1;
          break;
        }
      }
      assert(lg != -1);
      int f = 0;
      if (x == cent[lg][x]) f = 1;
      else if (y == cent[lg][x]) f = 1;
      else
      {
        int px = rep[lg][x][0], py = rep[lg][y][0];
        f = w[lg][px] > w[lg][py];
      }
      cout << (ic[lg][x] && dc[lg][y] && f ? "yes\n" : "no\n");
    }
    else
    {
      ans = 0;
      calcans(x, x, -inf);
      cout << ans << '\n';
    }
  }
}

Compilation message (stderr)

servers.cpp: In function 'int main()':
servers.cpp:150:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<long long int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  150 |   for (int i = 0; i < ed.size(); i++)
      |                   ~~^~~~~~~~~~~
servers.cpp:160:21: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<long long int, 3> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  160 |   for (tim = 0; tim < ed.size(); tim++)
      |                 ~~~~^~~~~~~~~~~

• Subtask 1: 0 / 2.5
• Subtask 2: 0 / 2.5
• Subtask 3: 2.5 / 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