Submission #231565

#	Time	Username	Problem	Language	Result	Execution time	Memory
231565		xiaowuc1	Bitaro’s Party (JOI18_bitaro)	C++14	100 / 100	839 ms	111352 KiB

bitaro

#include <algorithm>
#include <bitset>
#include <cassert>
#include <chrono>
#include <complex>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_set>
#include <vector>

using namespace std;

// BEGIN NO SAD
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define trav(a, x) for(auto& a : x)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) (int)(x).size()
#define derr if(1) cerr
typedef vector<int> vi;
// END NO SAD

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int SAVE = 100;
vector<pii> best[100005];
vector<int> edges[100005];

int excluded[100005];
int n;
int dp[100005];
void solve(int dest, int id) {
  memset(dp, -1, sizeof(dp));
  for(int i = 1; i <= dest; i++) {
    if(excluded[i] != id) dp[i] = max(dp[i], 0);
    for(int out: edges[i]) {
      if(dp[out] < 0) continue;
      dp[i] = max(dp[i], dp[out] + 1);
    }
  }
  cout << dp[dest] << "\n";
}

void solve() {
  int q;
  {
    int m;
    cin >> n >> m >> q;
    while(m--) {
      int a, b;
      cin >> a >> b;
      edges[b].push_back(a);
    }
  }
  int id = 0;
  for(int i = 1; i <= n; i++) {
    map<int, int> cache;
    best[i].emplace_back(0, i);
    for(int par: edges[i]) {
      id++;
      vector<pii> nbest;
      int a = 0; // best[i]
      int b = 0; // best[par]
      while(sz(nbest) < SAVE && (a < sz(best[i]) || b < sz(best[par]))) {
        bool achoose = true;
        if(a == sz(best[i])) achoose = false;
        else if(b < sz(best[par]) && best[par][b].first + 1 > best[i][a].first) achoose = false;
        if(achoose) {
          if(excluded[best[i][a].second] != id) {
            excluded[best[i][a].second] = id;
            nbest.push_back(best[i][a]);
          }
          a++;
        }
        else {
          if(excluded[best[par][b].second] != id) {
            excluded[best[par][b].second] = id;
            nbest.emplace_back(best[par][b].first+1, best[par][b].second);
          }
          b++;
        }
      }
      best[i].swap(nbest);
    }
  }
  memset(excluded, 0, sizeof(excluded));
  for(int qq = 1; qq <= q; qq++) {
    int dest;
    cin >> dest;
    int k;
    cin >> k;
    while(k--) {
      int x;
      cin >> x;
      excluded[x] = qq;
    }
    int ret = -2;
    bool found = false;
    for(pii out: best[dest]) {
      if(excluded[out.second] == qq) continue;
      ret = out.first;
      found = true;
      break;
    }
    if(found) {
      cout << ret << "\n";
      continue;
    }
    solve(dest, qq);
  }
}


// are there edge cases (N=1?)
// are array sizes proper (scaled by proper constant, for example 2* for koosaga tree)
// integer overflow?
// DS reset properly between test cases

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL); cout.tie(NULL);
  solve();
}

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