Submission #329896

#	Time	Username	Problem	Language	Result	Execution time	Memory
329896		VROOM_VARUN	Bitaro’s Party (JOI18_bitaro)	C++14	100 / 100	1462 ms	414572 KiB

bitaro

/*
ID: varunra2
LANG: C++
TASK: bitaro
*/

#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 (int)1e9
#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<int, int> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<int> 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

bool pr = false;

int ops = 0;

const int block = 350;
int n, m, q;
vector<bool> vis;
VI dists;
VVI adj;
vector<VII> vals;

void flip(vector<bool>& vis, VI& pos) { trav(x, pos) vis[x] = !vis[x]; }

priority_queue<pair<PII, int>> pq;

static bool cmp(int& a, int& b) { return dists[a] > dists[b]; }

void gen(int u) {
  VI use;
  use.PB(u);
  for (auto& x : adj[u]) {
    for (auto& val : vals[x]) {
      if (!dists[val.y]) {
        use.PB(val.y);
      }
      dists[val.y] = max(dists[val.y], val.x + 1);
    }
  }

  nth_element(use.begin(), use.begin() + min(block, sz(use)), use.end(), cmp);
  for (int i = 0; i < min(block, sz(use)); i++) {
    vals[u].PB(MP(dists[use[i]], use[i]));
  }
  for (auto& x : use) dists[x] = 0;
}

void init() {
  adj.resize(n);
  vals.resize(n);
  dists.assign(n, 0);
  vis.assign(n, false);
}

void preprocess() {
  for (int i = 0; i < n; i++) {
    gen(i);
  }
}

void stupid(VI& dist) {
  for (int i = n - 1; ~i; i--) {
    if (dist[i] == -1) continue;
    for (auto& x : adj[i]) dist[x] = max(dist[x], dist[i] + 1);
  }
}

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

  cin >> n >> m >> q;
  if (n < 20) pr = true;

  init();

  for (int i = 0; i < m; i++) {
    int u, v;
    cin >> u >> v;
    u--, v--;
    adj[v].PB(u);
  }

  bool calc = false;

  vector<bool> vis1(n, false);

  while (q--) {
    int u, cnt;
    cin >> u >> cnt;
    u--;
    VI bad;
    for (int i = 0; i < cnt; i++) {
      int v;
      cin >> v;
      v--;
      bad.PB(v);
    }

    flip(vis1, bad);

    if (cnt < block - 1) {
      if (!calc) {
        calc = true;
        preprocess();
      }
      int ret = -1;
      for (int i = 0; i < sz(vals[u]); i++) {
        if (!vis1[vals[u][i].y]) {
          ret = max(vals[u][i].x, ret);
        }
      }
      cout << ret << '\n';
    } else {
      VI dist(n, -1);
      dist[u] = 0;
      stupid(dist);
      int ret = -1;
      for (int i = 0; i < n; i++) {
        if (vis1[i]) continue;
        ret = max(ret, dist[i]);
      }
      cout << ret << '\n';
    }
    flip(vis1, bad);
  }

  // if (pr) trav(x, vals) debug(x);

  debug(ops);

  return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:19:20: warning: statement has no effect [-Wunused-value]
   19 | #define debug(...) 42
      |                    ^~
bitaro.cpp:177:3: note: in expansion of macro 'debug'
  177 |   debug(ops);
      |   ^~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 86 / 86