Submission #94471

#	Time	Username	Problem	Language	Result	Execution time	Memory
94471		wxh010910	Toy Train (IOI17_train)	C++17	100 / 100	592 ms	1528 KiB

train

#include <bits/stdc++.h>
#include "train.h"

using namespace std;

vector<int> who_wins(vector<int> a, vector<int> r, vector<int> u, vector<int> v) {
  int n = a.size(), m = u.size();
  vector<vector<int>> adj(n);
  vector<int> deg(n);
  for (int i = 0; i < m; ++i) {
    adj[v[i]].push_back(u[i]);
    ++deg[u[i]];
  }
  while (true) {
    vector<int> win = r;
    {
      vector<int> degree = deg;
      queue<int> q;
      for (int i = 0; i < n; ++i) {
        if (win[i]) {
          q.push(i);
        }
      }
      while (!q.empty()) {
        int x = q.front();
        q.pop();
        for (auto y : adj[x]) {
          if (!win[y]) {
            if (a[y] || !--degree[y]) {
              win[y] = 1;
              q.push(y);
            }
          }
        }
      }
    }
    {
      vector<int> degree = deg;
      queue<int> q;
      for (int i = 0; i < n; ++i) {
        if (!win[i]) {
          q.push(i);
        }
      }
      while (!q.empty()) {
        int x = q.front();
        q.pop();
        for (auto y : adj[x]) {
          if (win[y]) {
            if (!a[y] || !--degree[y]) {
              win[y] = 0;
              q.push(y);
            }
          }
        }
      }
    }
    bool changed = false;
    for (int i = 0; i < n; ++i) {
      if (r[i] && !win[i]) {
        changed = true;
        r[i] = 0;
      }
    }
    if (!changed) {
      return win;
    }
  }
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 11 / 11
• Subtask 4: 11 / 11
• Subtask 5: 12 / 12
• Subtask 6: 51 / 51