oj.uz

Submission #761469

# Submission time Handle Problem Language Result Execution time Memory
761469 2023-06-19T18:14:01 Z Sam_a17 Papričice (COCI20_papricice) C++17
110 / 110
 188 ms 29256 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
 
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(long double t) {cerr << t;}
void print(unsigned long long 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, class V> void print(T v[],V n) {cerr << "["; for(int i = 0; i < n; i++) {print(v[i]); cerr << " "; } 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 << "]";}
template <class T> void print(deque <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
 
// for random generations
// mt19937 myrand(chrono::steady_clock::now().time_since_epoch().count());
mt19937 myrand(373);
 
// 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 == "input") {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
  } else {
    // freopen("skis.in", "r", stdin);
    // freopen("skis.out", "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 = 2e5 + 10;
vector<pair<int, int>> adj[N];
int n, sz[N], cur_edge, ans;
bool vis[N];

multiset<int> up, not_up;

void dfs_sz(int node, int parent) {
  sz[node] = 1;
  for(auto i: adj[node]) {
    if(i.first == parent) continue;
    dfs_sz(i.first, node);
    sz[node] += sz[i.first];
  }
}

void relax(int a, int b, int c) {
  ans = min(ans, max({a, b, c}) - min({a, b, c}));
}

void dfs(int node, int parent) {
  if(node != 1) {
    // up case
    int other = n - sz[node];
    auto it = up.lower_bound(other / 2 + sz[node]);
    if(it != up.end()) {
      int cur = *it - sz[node];
      relax(sz[node], cur, n - cur - sz[node]);
    }

    if(it != up.begin()) {
      it = prev(it);
      int cur = *it - sz[node];
      relax(sz[node], cur, n - cur - sz[node]);
    }

    // not_up case
    if(!not_up.empty()) {
      other = n - sz[node];
      it = not_up.lower_bound(other / 2);
      if(it != not_up.end()) {
        int cur = *it;
        relax(sz[node], cur, n - cur - sz[node]);
      }

      if(it != not_up.begin()) {
        it = prev(it);
        int cur = *it;
        relax(sz[node], cur, n - cur - sz[node]);
      }
    }
  }

  up.insert(sz[node]);
  for(auto i: adj[node]) {
    if(i.first == parent) continue;
    dfs(i.first, node); 
  }

  up.erase(up.find(sz[node]));
  not_up.insert(sz[node]);
}

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

  dfs_sz(1, 0);

  dfs(1, 0);
  
  cout << ans << '\n';
}
 
int main() {
  setIO();
 
  auto solve = [&](int test_case)-> void {
    for(int i = 1; i <= test_case; i++) {
      solve_();
    }
  };
 
  int test_cases = 1;
  // cin >> test_cases;
  solve(test_cases);
 
  return 0;
}

Compilation message

papricice.cpp: In function 'void setIO(std::string)':
papricice.cpp:70:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
papricice.cpp:71:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 2 ms 5036 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct

Subtask #2
35.0 / 35.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 2 ms 5036 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 3 ms 5180 KB Output is correct
7 Correct 4 ms 5176 KB Output is correct
8 Correct 3 ms 5204 KB Output is correct
9 Correct 3 ms 5204 KB Output is correct
10 Correct 3 ms 5204 KB Output is correct

Subtask #3
60.0 / 60.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 2 ms 5036 KB Output is correct
3 Correct 3 ms 4948 KB Output is correct
4 Correct 3 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 3 ms 5180 KB Output is correct
7 Correct 4 ms 5176 KB Output is correct
8 Correct 3 ms 5204 KB Output is correct
9 Correct 3 ms 5204 KB Output is correct
10 Correct 3 ms 5204 KB Output is correct
11 Correct 160 ms 24976 KB Output is correct
12 Correct 188 ms 25012 KB Output is correct
13 Correct 157 ms 25572 KB Output is correct
14 Correct 160 ms 25388 KB Output is correct
15 Correct 158 ms 24968 KB Output is correct
16 Correct 108 ms 24772 KB Output is correct
17 Correct 139 ms 25144 KB Output is correct
18 Correct 162 ms 29256 KB Output is correct
19 Correct 147 ms 25352 KB Output is correct
20 Correct 186 ms 25024 KB Output is correct