Submission #1148360

#	Time	Username	Problem	Language	Result	Execution time	Memory
1148360		akamizane	Bitaro’s Party (JOI18_bitaro)	C++20	100 / 100	894 ms	148136 KiB

bitaro

#include<bits/stdc++.h>
 
using namespace std;

#define debug(...) 40

using ll = long long;
using pii = pair<int,int>;

// #define int long long
#define el cout << '\n'
#define fi first
#define se second
#define pb push_back
#define all(x) x.begin(), x.end()
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FOD(i, a, b) for (int i = (a); i >= (b); i--)
#define REP(i, n) for (int i = 0; i < (n); i++)
template <class T1, class T2>bool chmax(T1 &a, T2 b){return a < b ? a = b, 1 : 0;}
template <class T1, class T2>bool chmin(T1 &a, T2 b){return a > b ? a = b, 1 : 0;}

void setIO(string s) {
  // freopen((s + ".inp").c_str(), "r", stdin);
  // freopen((s + ".out").c_str(), "w", stdout);
    freopen((s+".in").c_str(),"r",stdin);
    freopen((s+".out").c_str(),"w",stdout);
}

const int maxn = 2e5 + 5;
const int mod = 998244353;
const ll inf = 1e18;

vector<int> ad[maxn], cur;
vector<array<int, 2>> node[maxn];
int dis[maxn], vis[maxn], bad[maxn], dp[maxn];

int32_t main() {
  // setIO("262144");
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n, m, q;
  cin >> n >> m >> q;
  REP(i, m){
    int u, v;
    cin >> u >> v;
    ad[v].pb(u);
  }
  const int block = 100;
  for (int i = 1; i <= n; i++, cur.clear()){
    for (auto j : ad[i]){
      for (auto [w, u] : node[j]){
        if (vis[u] == i) chmax(dis[u], w + 1);
        else vis[u] = i, dis[u] = w + 1, cur.pb(u);
      }
    }
    for (auto u : cur) node[i].pb({dis[u], u});
    node[i].pb({0, i});
    sort(node[i].rbegin(), node[i].rend());
    while(node[i].size() > block) node[i].pop_back();
  }
  FOR(cnt, 1, q){
    int t, k, x, ans = -1;
    cin >> t >> k;
    REP(i, k){
      int x;
      cin >> x;
      bad[x] = cnt;
    }
    if (k < block){
      for (auto [w, u] : node[t]){
        if (bad[u] != cnt){
          ans = w;
          break;
        }
      }
    }
    else{
      fill(dp, dp + n + 1, -1);
      for (int i = 1; i <= t; i++){
        if (bad[i] != cnt) dp[i] = 0;
        for (auto j : ad[i]){
          if (dp[j] != -1) chmax(dp[i], dp[j] + 1);
        }
      }
      ans = dp[t];
    }
    cout << ans << "\n";
  }
  return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'void setIO(std::string)':
bitaro.cpp:25:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |     freopen((s+".in").c_str(),"r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:26:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   26 |     freopen((s+".out").c_str(),"w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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