Submission #646838

#	Time	Username	Problem	Language	Result	Execution time	Memory
646838		tvladm2009	Bitaro’s Party (JOI18_bitaro)	C++14	14 / 100	2077 ms	149100 KiB

bitaro

#include <bits/stdc++.h>

using ll = long long;

int const nmax = 100000;

int dp[1 + nmax];
std::vector<int> g[1 + nmax];
std::vector<std::pair<int, int>> sol[1 + nmax];
bool viz[1 + nmax], b[1 + nmax];

int main() {
  int n, m, q;
  scanf("%d%d%d", &n, &m, &q);
  for(int i = 1;i <= m; i++) {
    int u, v;
    scanf("%d%d", &u, &v);
    g[u].push_back(v);
  }

  for(int i = 1;i <= n; i++)
    sol[i].push_back({0, i});
  for(int u = 1;u <= n; u++) {
    std::sort(sol[u].rbegin(), sol[u].rend());
    for(auto p : sol[u])
      viz[p.second] = false;
    std::vector<std::pair<int, int>> aux;
    for(auto v : sol[u]) {
      if(aux.size() >= 120)
        break;
      if(!viz[v.second]) {
        aux.push_back(v);
        viz[v.second] = 1;
      }
    }
    std::swap(sol[u], aux);

    for(int v : g[u]) {
      for(auto p : sol[u])
        sol[v].push_back({p.first + 1, p.second});
    }
  }

  while(q--) {
    int to, y;
    std::cin >> to >> y;
    std::vector<int> c(y + 1);
    for(int i = 1;i <= y; i++) {
      int v;
      std::cin >> v;
      c[i] = v;
      b[v] = true;
    }

    if(y >= 120) {
      for(int i = 1;i <= n; i++) {
        if(b[i])
          dp[i] = -1;
        else
          dp[i] = 0;
      }
      for(int i = 1;i <= n; i++) {
        if(dp[i] == -1)
          continue;
        for(int u : g[i])
          dp[u] = std::max(dp[u], dp[i] + 1);
      }
      printf("%d\n", dp[to]);
    } else {
      int ans = -1;
      for(auto p : sol[to]) {
        if(!b[p.second])
          ans = std::max(ans, p.first);
      }
      printf("%d\n", ans);
    }

    for(int i = 1;i <= y; i++)
      b[c[i]] = false;
  }
  return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:14:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |   scanf("%d%d%d", &n, &m, &q);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:17:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |     scanf("%d%d", &u, &v);
      |     ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 0 / 86