Submission #719086

#	Time	Username	Problem	Language	Result	Execution time	Memory
719086		Sam_a17	Village (BOI20_village)	C++17	100 / 100	140 ms	38016 KiB

Village

#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(x) __builtin_popcount(x)
 
#define pb push_back
#define popf pop_front
#define popb pop_back
 
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(deque <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 long long N = 2e5 + 10, inf = 1e8;
vector<int> adj[N];
long long dp[N][2], each[N], pat[N];
vector<pair<int, int>> dpp[N][2];
long long n, max_ans;
long long sz[N];

void dfs(int node, int parent) {
  int c = 0;
  sz[node] = 1;
  for(auto i: adj[node]) {
    if(i == parent) continue;
    dfs(i, node);
    sz[node] += sz[i];
    c++;
  }

  max_ans += 2 * min(sz[node], n - sz[node]);

  if(!c) {
    dp[node][0] = 0;
    dp[node][1] = inf;
  } else {

    long long s = 0;
    for(auto i: adj[node]) {
      if(i == parent) continue;
      dp[node][0] += dp[i][1];
      dp[node][0] = min(dp[node][0], inf);

      s += min(dp[i][1], dp[i][0] + 2);
      if(dp[i][0] + 2 <= dp[i][1]) {
        dpp[node][1].push_back({i, 1});
      } else {
        dpp[node][1].push_back({i, 0});
      }
    }

    long long sx = INT32_MAX;
    int it = 0;

    pair<int, int> pp;
    for(auto i: adj[node]) {
      if(i == parent) continue;

      if(s - min(dp[i][1], dp[i][0] + 2) + min(dp[i][1] + 2, dp[i][0] + 2) < sx) {
        sx = s - min(dp[i][1], dp[i][0] + 2) + min(dp[i][1] + 2, dp[i][0] + 2);
        pp = {i, 1};
      }
      it++;
    }

    for(auto &i: dpp[node][1]) {
      if(i.first == pp.first) {
        i.second = 1;
      }
    }
    dp[node][1] = sx;
  } 
}

void gen_edges(int node, int state, int parent) {
  if(state == 0) {
    for(auto i: adj[node]) {
      if(i == parent) continue;
      gen_edges(i, 1, node);
    }
  } else {
    int cnt = 0;
    for(auto i: dpp[node][1]) {
      if(i.second == 1) {
        cnt++;
        swap(each[node], each[i.first]);
        if(dp[i.first][0] > dp[i.first][1]) {
          gen_edges(i.first, 1, node);
        } else {
          gen_edges(i.first, 0, node);
        }
      } else {
        gen_edges(i.first, 1, node);
      }
    }

    assert(cnt >= 1);
  }
}

int d[101][101];

void dist (int a, int b) {
  queue<int> q;
  vector<int> dist(n + 1);
  dist[a] = 1;
  q.push(a);

  while(!q.empty()) {
    auto u = q.front();
    q.pop();
    for(auto i: adj[u]) {
      if(dist[i]) continue;
      dist[i] = dist[u] + 1;
      q.push(i);
    }
  }

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

int dfsik(int node, int parent) {
  sz[node] = 1;
  for(auto i: adj[node]) {
    if(i == parent) continue;
    sz[node] += dfsik(i, node);
  }
  return sz[node];
}
 
int find_center(int node, int parent) {
  for(auto i: adj[node]) {
    if (i == parent) continue;
    if (2 * sz[i] > n) {
      return find_center(i, node);
    }
  }
  return node;
}
 
int centroid(int u) {
  dfsik(u, 0);
  u = find_center(u, 0);
  return u;
}

vector<int> path;
void dfs_order(int node, int parent) {
  path.push_back(node);
  for(auto i: adj[node]) {
    if(i == parent) continue;
    dfs_order(i, node);
  }
}
 

void solve_() {
  cin >> n;

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

  dfs(1, 0);

  for(int i = 1; i <= n; i++) {
    each[i] = i;
  }
  gen_edges(1, 1, 0);

  for(int i = 1; i <= n; i++) {
    pat[each[i]] = i;
    assert(each[i] != i);
  }

  vector<int> pte;
  int bans = 0;

  int cen = centroid(1);
  dfs_order(cen, -1);

  vector<int> which(n + 1);

  for(int i = 0; i < n; i++) {
    which[path[i]] = path[(i + n / 2) % n];
  }

  cout << dp[1][1] << " " << max_ans << '\n';
  for(int i = 1; i <= n; i++) {
    cout << pat[i] << " ";
  }
  cout << '\n';
  for(int i = 1; i <= n; i++) {
    cout << which[i] << " ";
  }
  cout << '\n';
}
 
int main() {
  setIO();
 
  auto solve = [&](int test_case)-> void {
    while(test_case--) {
      solve_();
    }
  };
 
  int test_cases = 1;
  // cin >> test_cases;
  solve(test_cases);
 
  return 0;
} 

Compilation message (stderr)

Village.cpp: In function 'void solve_()':
Village.cpp:239:7: warning: unused variable 'bans' [-Wunused-variable]
  239 |   int bans = 0;
      |       ^~~~
Village.cpp: In function 'void setIO(std::string)':
Village.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Village.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 + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 38 / 38
• Subtask 3: 50 / 50