Submission #783863

#	Time	Username	Problem	Language	Result	Execution time	Memory
783863		tvladm2009	Cats or Dogs (JOI18_catdog)	C++17	0 / 100	1 ms	2644 KiB

catdog

#include <bits/stdc++.h>
#include "catdog.h"

using namespace std;

const int N = (int) 1e5 + 7;
const int INF = (int) 1e9;
int n;
int par[N];
int dp1[N];
int dp2[N];
int dp3[N];
int dp4[N];
int cost1[N];
int cost2[N];
vector<int> g[N];

void build(int a, int p = 0) {
  par[a] = p;
  vector<int> kids;
  for (auto &b : g[a]) {
    if (b != p) {
      kids.push_back(b);
      build(b, a);
    }
  }
  g[a] = kids;
}

void dfs(int a) {
  dp1[a] = 0;
  dp2[a] = 0;
  for (auto &b : g[a]) {
    dfs(b);
    dp1[a] += dp3[b];
    dp2[a] += dp4[b];
  }
  dp1[a] += cost1[a];
  dp2[a] += cost2[a];

  dp3[a] = min(dp1[a], dp2[a] + 1);
  dp4[a] = min(dp2[a], dp1[a] + 1);
}

void initialize(int nn, vector<int> a, vector<int> b) {
  n = nn;
  for (int i = 1; i < n; i++) {
    g[a[i]].push_back(b[i]);
    g[b[i]].push_back(a[i]);
  }
  build(1);
}

void change(int v, int c1, int c2) {
  cost1[v] = c1;
  cost2[v] = c2;
  dfs(1);
}

int cat(int v) {
  change(v, INF, 0);
  return min(dp1[1], dp2[1]);
}

int dog(int v) {
  change(v, 0, INF);
  return min(dp1[1], dp2[1]);
}

int neighbor(int v) {
  change(v, 0, 0);
  return min(dp1[1], dp2[1]);
}

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