Submission #336584

#	Time	Username	Problem	Language	Result	Execution time	Memory
336584		VROOM_VARUN	Political Development (BOI17_politicaldevelopment)	C++14	100 / 100	1394 ms	27116 KiB

politicaldevelopment

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

#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

int n, k;
vector<SETI> adj;
VI deg;
vector<bool> use;
int mx = 0;

void init() {
  adj.resize(n);
  deg.assign(n, 0);
  use.assign(n, false);
}

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

  cin >> n >> k;

  init();

  for (int i = 0; i < n; i++) {
    int d;
    cin >> d;
    for (int j = 0; j < d; j++) {
      int u;
      cin >> u;
      adj[i].insert(u);
      adj[u].insert(i);
    }
  }

  rep(u, 0, n) trav(v, adj[u]) { deg[u]++; }

  queue<int> q;

  for (int i = 0; i < n; i++) {
    if (deg[i] <= k) q.push(i);
  }

  // debug(deg);
  // debug(q);

  while (!q.empty()) {
    // debug("debugging adj :imp:");
    // trav(x, adj) debug(x);
    int u = q.front();
    q.pop();
    VI cur;
    trav(x, adj[u]) if (!use[x]) cur.PB(x);
    for (int i = 0; i < (1 << sz(cur)); i++) {
      int val = __builtin_popcount(i);
      if (val < mx) continue;
      VI now;
      now.PB(u);
      for (int j = 0; j < sz(cur); j++) {
        if (i & (1 << j)) now.PB(cur[j]);
      }
      bool ok = true;
      for (int j = 0; j < sz(now) and ok; j++) {
        for (int kk = j + 1; kk < sz(now) and ok; kk++) {
          if (adj[now[j]].find(now[kk]) == adj[now[j]].end()) ok = false;
        }
      }
      // debug(cur)
      if (ok) mx = max(mx, val + 1);
    }
    use[u] = true;
    for (auto& x : cur) {
      adj[x].erase(u), deg[x]--;
      if (deg[x] <= k) q.push(x);
      adj[u].erase(x);
    }
  }

  cout << mx << '\n';

  return 0;
}

Compilation message (stderr)

politicaldevelopment.cpp: In function 'int main()':
politicaldevelopment.cpp:90:21: warning: unused variable 'v' [-Wunused-variable]
   90 |   rep(u, 0, n) trav(v, adj[u]) { deg[u]++; }
      |                     ^
politicaldevelopment.cpp:48:31: note: in definition of macro 'trav'
   48 | #define trav(a, x) for (auto& a : x)
      |                               ^

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 23 / 23
• Subtask 4: 38 / 38
• Subtask 5: 23 / 23