Submission #473787

#	Time	Username	Problem	Language	Result	Execution time	Memory
473787		Lain	Power Plant (JOI20_power)	C++17	100 / 100	212 ms	34372 KiB

power

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

template<class Fun>
class y_combinator_result {
  Fun fun_;
public:
  template<class T>
  explicit y_combinator_result(T &&fun): fun_(std::forward<T>(fun)) {}
 
  template<class ...Args>
  decltype(auto) operator()(Args &&...args) {
    return fun_(std::ref(*this), std::forward<Args>(args)...);
  }
};
 
template<class Fun>
decltype(auto) y_combinator(Fun &&fun) {
  return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun));
}

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

  int n;
  cin >> n;
  vector<vector<int>> g(n);
  for (int i = 0; i < n-1; i++) {
    int u,v;
    cin >> u >> v;
    u--,v--;
    g[u].push_back(v);
    g[v].push_back(u);
  }
  string gen;
  cin >> gen;

  vector<int> dp(n);
  int ans = 0;
  y_combinator([&](auto self, int s, int p)->void {
    vector<int> c;
    for (auto& u : g[s]){
      if (u==p) continue;
      self(u,s);
      c.push_back(dp[u]);
    }
    if (gen[s] == '0') {
      for (auto& x : c) dp[s] += x;
    }
    else {
      if (c.size() == 0)
        dp[s] = 1;
      else {
        ans = max(ans,*max_element(c.begin(),c.end())+1);
        for (auto& x : c)
          dp[s] += x;
        dp[s]--;
        dp[s] = max(dp[s],1);
      }
    }
    ans = max(dp[s],ans);
  })(0,-1);
  cout << ans << '\n';
}

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 53 / 53