Submission #937096

#	Time	Username	Problem	Language	Result	Execution time	Memory
937096		nguyentunglam	Cats or Dogs (JOI18_catdog)	C++17	38 / 100	3047 ms	7772 KiB

catdog

#include<bits/stdc++.h>
#define fi first
#define se second
#define endl "\n"
#define ii pair<int, int>
using namespace std;

const int N = 1e5 + 10;

int n;

bool bug;

vector<int> adj[N];

int f[N], g[N], a[N];

void dfs(int u, int par) {
  f[u] = g[u] = 0;
  if (a[u] == 1) f[u] = 1e9;
  if (a[u] == 2) g[u] = 1e9;
//  if (bug && u == 2) {
//    cout << f[u] << " " << g[y] << endl
//  }
  for(int &v : adj[u]) if (v != par) {
    dfs(v, u);
    f[u] += min(f[v], g[v] + 1);
    g[u] += min(g[v], f[v] + 1);
  }
}

void initialize (int N, vector<int> A, vector<int> B) {
  n = N;
  for(int i = 0; i < n - 1; i++) {
    adj[A[i]].push_back(B[i]);
    adj[B[i]].push_back(A[i]);
  }
}

int cat(int v) {
  a[v] = 1;
  dfs(1, 0);
  return min(f[1], g[1]);
}

int dog(int v) {
  a[v] = 2;
  bug = 1;
  dfs(1, 0);
  return min(f[1], g[1]);
}

int neighbor(int v) {
  a[v] = 0;
  dfs(1, 0);
  return min(f[1], g[1]);
}

#ifdef ngu
int main() {

  freopen ("task.inp", "r", stdin);
  freopen ("task.out", "w", stdout);

  int n; cin >> n;

  vector<int> a(n - 1), b(n - 1);

  for(int i = 0; i < n - 1; i++) cin >> a[i] >> b[i];

  initialize(n, a, b);

  int q; cin >> q;

  while (q--) {
    int t, v; cin >> t >> v;
    if (t == 1) cout << cat(v);
    if (t == 2) cout << dog(v);
    if (t == 3) cout << neighbor(v);
    cout << endl;
  }
}
#endif // ngu

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