oj.uz

Submission #584026

# Submission time Handle Problem Language Result Execution time Memory
584026 2022-06-26T16:43:43 Z Sam_a17 Link (CEOI06_link) C++14
76 / 100
 1500 ms 34160 KB 
#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
//#include "temp.cpp"
#include <cstdio>
using namespace std;

#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif

#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define uniq(x) x.resize(unique(all(x)) - x.begin());
#define blt __builtin_popcount

#define pb push_back
#define popf pop_front
#define popb pop_back
#define ld long double
#define ll long long

void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
void print(long double t) {cerr << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T> void print(T v[],T n) {cerr << "["; for(int i = 0; i < n; i++) {cerr << v[i] << " ";} cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'

// for grid problems
int dx[8] = {-1,0,1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};

// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
  fastIO();

  if (str != "") {
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
  }
}

// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 5e5 + 10, inf = 1e9;
int n, k, in[N], dist[N], answ;
vector<int> adj[N];
bool used[N];

int cycle(int node) {
  // dbg(node)
  int cur = node;
  vector<int> path;
  while(!used[cur]) {
    used[cur] = true;
    path.push_back(cur);
    cur = adj[cur][0];
  }

  // dbg(path)

  // dbg(sz(path))

  for(auto i: path) {
    used[i] = false;
  }

  {
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>> > q;

    for(auto i: path) {
      q.push({dist[i], i});
    }

    while(!q.empty()) {
      auto u = q.top();
      q.pop();
      if(used[u.second]) {
        continue;
      }
      used[u.second] = true;

      if(u.first >= k) {
        break;
      }

      for(auto i: adj[u.second]) {
        if(dist[i] > dist[u.second] + 1) {
          dist[i] = dist[u.second] + 1;
          q.push({dist[i], i});
        }
      }
    }
  }
  
  int m = sz(path);

  int mini = 0;
  for(int i = 0; i < m; i++) {
    if(dist[path[i]] == inf) {
      ++mini;
    }
  }

  if(!mini) {
    for(auto i: path) {
      used[i] = true;
    }
    return 0;
  }

  int lst = -1;
  vector<int> ptr(m, 0);
  for(int i = 2 * m - 1; i >= 0; i--) {
    if(dist[path[i % m]] == inf) {
      lst = i % m;
      ptr[lst] = lst;
    } else if(lst != -1) {
      ptr[i % m] = lst;
    }
  }

  for(int start = 0; start < min(k, m); start++) {
    int road = 0, pos = start, ansi = 0;
    while(true) {
      road += ptr[pos] - pos;
      pos = ptr[pos];
      
      if(road >= m) {
        break;
      }

      ansi++, road += k;
      pos += k, pos %= m;
    }

    mini = min(mini, ansi);
  }

  //
  for(auto i: path) {
    used[i] = true;
  }

  return mini;
}

void solve_() {
  cin >> n >> k;
  for(int i = 1; i <= n; i++) {
    int a, b; cin >> a >> b;
    adj[a].push_back(b); in[b]++;
  }

  for(int i = 2; i <= n; i++) {
    if(!in[i]) {
      adj[1].push_back(i);
      in[i]++;
      answ++;
    }
  }

  {
    for(int i = 1; i <= n; i++) {
      dist[i] = inf;
    }

    queue<pair<int, int>> q;
    q.push({1, 0});
    used[1] = true;

    while(!q.empty()) {
      auto u = q.front();
      q.pop();

      int curr = u.second + 1;
      if(curr > k) {
        answ++, curr = 1;
      }

      for(auto i: adj[u.first]) {
        
        dist[i] = min(dist[i], curr);
        in[i]--;
        if(!in[i] && !used[i]) {
          used[i] = true;
          q.push({i, dist[i]}); 
        }
      }
    }
  }

  for(int i = 1; i <= n; i++) {
    if(!used[i]) {
      // we get cycle
      answ += cycle(i);
    }
  }


  printf("%d\n", answ);
}

int main () {
  setIO("");

  auto solve = [&](int test_case)-> void {
    while(test_case--) {
      solve_();
    }
  };

  int test_cases = 1;
  solve(test_cases);

  return 0;
}

Compilation message

link.cpp: In function 'void setIO(std::string)':
link.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
link.cpp:66:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   66 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
76.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 11988 KB Output is correct
2 Incorrect 6 ms 11988 KB Output isn't correct
3 Incorrect 7 ms 12016 KB Output isn't correct
4 Execution timed out 1568 ms 12116 KB Time limit exceeded
5 Execution timed out 1580 ms 12244 KB Time limit exceeded
6 Incorrect 14 ms 13416 KB Output isn't correct
7 Correct 21 ms 14116 KB Output is correct
8 Correct 27 ms 15032 KB Output is correct
9 Correct 43 ms 16508 KB Output is correct
10 Correct 39 ms 16540 KB Output is correct
11 Correct 81 ms 19652 KB Output is correct
12 Correct 108 ms 20136 KB Output is correct
13 Correct 131 ms 22856 KB Output is correct
14 Correct 180 ms 24872 KB Output is correct
15 Correct 242 ms 27584 KB Output is correct
16 Incorrect 256 ms 29596 KB Output isn't correct
17 Correct 310 ms 32048 KB Output is correct
18 Correct 320 ms 33216 KB Output is correct
19 Correct 346 ms 33276 KB Output is correct
20 Correct 333 ms 33268 KB Output is correct
21 Correct 354 ms 33544 KB Output is correct
22 Correct 324 ms 34080 KB Output is correct
23 Correct 340 ms 33792 KB Output is correct
24 Correct 319 ms 34140 KB Output is correct
25 Correct 350 ms 34160 KB Output is correct