Submission #203687

#	Time	Username	Problem	Language	Result	Execution time	Memory
203687		fedoseevtimofey	Cats or Dogs (JOI18_catdog)	C++14	38 / 100	3076 ms	6504 KiB

catdog

#include <iostream>
#include <string>
#include <vector>
#include <queue>
#include <deque>
#include <stack>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <random>
#include <complex>
#include <iomanip>
#include <cassert>
#include <functional>
          
using namespace std;
        
typedef long long ll;
 
const int N = 1e5 + 7;
vector <int> g[N];
 
void initialize(int n, vector <int> a, vector <int> b) {
  for (int i = 0; i + 1 < n; ++i) {
    --a[i], --b[i];
    g[a[i]].push_back(b[i]);
    g[b[i]].push_back(a[i]);
  }
}
 
bool have_cat[N], have_dog[N];
 
int dp[N][3];
 
const int Inf = 1e9;
 
void dfs(int u, int p) {
  dp[u][0] = dp[u][1] = 0;
  for (auto v : g[u]) {
    if (v != p) {
      dfs(v, u);
      dp[u][0] += min(dp[v][0], dp[v][1] + 1);
      dp[u][1] += min(dp[v][1], dp[v][0] + 1);
    }
  }
  if (have_cat[u]) {
    dp[u][1] = Inf;
  }
  if (have_dog[u]) {
    dp[u][0] = Inf;
  }
}
 
int cat(int v) {
  --v;
  have_cat[v] = true;
  dfs(0, -1);
  int ans = Inf;
  for (int i = 0; i < 2; ++i) ans = min(ans, dp[0][i]);
  return ans;
}
 
int dog(int v) {
  --v;
  have_dog[v] = true;
  dfs(0, -1);
  int ans = Inf;
  for (int i = 0; i < 2; ++i) ans = min(ans, dp[0][i]);
  return ans;
}
 
int neighbor(int v) {
  --v;
  have_cat[v] = have_dog[v] = false;
  dfs(0, -1);
  int ans = Inf;
  for (int i = 0; i < 2; ++i) ans = min(ans, dp[0][i]);
  return ans;
}
  
#ifdef LOCAL
int main() {
  ios_base::sync_with_stdio(false); cin.tie(0);
#ifdef LOCAL
  freopen("input.txt", "r", stdin);
#endif
  int n;
  cin >> n;
  vector <int> a(n - 1), b(n - 1);
  for (int i = 0; i + 1 < n; ++i) {
    cin >> a[i] >> b[i];
  }
  initialize(n, a, b);  
  int q;
  cin >> q;
  for (int i = 0; i < q; ++i) {
    int t, v;
    cin >> t >> v;
    if (t == 1) {
      cout << cat(v) << '\n';
    } else if (t == 2) {
      cout << dog(v) << '\n';
    } else {
      cout << neighbor(v) << '\n';
    }
  }
}
#endif

• Subtask 1: 8 / 8
• Subtask 2: 30 / 30
• Subtask 3: 0 / 62