oj.uz

Submission #584051

# Submission time Handle Problem Language Result Execution time Memory
584051 2022-06-26T17:22:49 Z Sam_a17 Link (CEOI06_link) C++14
100 / 100
 386 ms 34076 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;
  }

  // dbg("done")

  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) {
      // assert(lst != -1);
      ptr[i % m] = lst;
    }
  }

  // dbg(ptr)

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

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

    // assert(false);
    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});
    dist[1] = 0;
    used[1] = true;

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

      // dbg(u)
      if(u.second > k) {
        dist[u.first] = 1;
        answ++;
      }

      for(auto i: adj[u.first]) {
        in[i]--;
        dist[i] = min(dist[i], dist[u.first] + 1);

        if(!in[i]) {
          used[i] = true;
          q.push({i, dist[i]}); 
        }
      }
    }
  }

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

  // dbg(answ)

  for(int i = 1; i <= n; i++) {
    if(!used[i]) {
      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
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 11988 KB Output is correct
2 Correct 7 ms 11988 KB Output is correct
3 Correct 7 ms 12116 KB Output is correct
4 Correct 8 ms 12116 KB Output is correct
5 Correct 8 ms 12244 KB Output is correct
6 Correct 15 ms 13364 KB Output is correct
7 Correct 21 ms 14164 KB Output is correct
8 Correct 29 ms 15108 KB Output is correct
9 Correct 54 ms 16564 KB Output is correct
10 Correct 40 ms 16484 KB Output is correct
11 Correct 107 ms 19656 KB Output is correct
12 Correct 114 ms 20220 KB Output is correct
13 Correct 133 ms 23008 KB Output is correct
14 Correct 155 ms 24880 KB Output is correct
15 Correct 237 ms 27548 KB Output is correct
16 Correct 269 ms 29576 KB Output is correct
17 Correct 325 ms 32000 KB Output is correct
18 Correct 342 ms 33192 KB Output is correct
19 Correct 322 ms 33384 KB Output is correct
20 Correct 368 ms 33300 KB Output is correct
21 Correct 330 ms 33624 KB Output is correct
22 Correct 386 ms 34040 KB Output is correct
23 Correct 309 ms 33568 KB Output is correct
24 Correct 332 ms 34012 KB Output is correct
25 Correct 350 ms 34076 KB Output is correct