Submission #415718

#	Time	Username	Problem	Language	Result	Execution time	Memory
415718		MarcoMeijer	Cats or Dogs (JOI18_catdog)	C++14	0 / 100	17 ms	23820 KiB

catdog

#include "catdog.h"
#include <bits/stdc++.h>
using namespace std;

typedef pair<int,int> ii;
typedef long long ll;
typedef pair<int,int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<ll> vll;

#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define RE(a,b) REP(a,0,b)
#define RE1(a,b) REP(a,1,b+1)
#define FOR(a,b) for(auto& a : b)
#define pb push_back
#define all(a) a.begin(),a.end()
#define fi first
#define se second

const int INF	= 1e9;
const int MX	= 5e5;
const int N	  = 1<<20;
const int MOD	= 1e9+7;

int n;
int a[MX];

// tree stuff
vi adj[MX], chl[MX];
int sz[MX], par[MX], dep[MX];
void dfs(int u, int p) {
  sz[u] = 1;
  par[u] = p;
  dep[u] = dep[p]+1;
  FOR(v,adj[u]) {
    if(v == p) continue;
    dfs(v,u);
    sz[u] += sz[v];
  }
}

void initialize(int N, std::vector<int> A, std::vector<int> B) {
  n = N;
  RE(i,n-1) {
    adj[A[i]].pb(B[i]);
    adj[B[i]].pb(A[i]);
  }
  dfs(1,1);
}

// dp
int dp[MX][2];
void dfsDP(int u) {
  FOR(v,chl[u]) dfsDP(v);
  
  RE(i,2) {
    dp[u][i] = 0;
    FOR(v,chl[u])
      dp[u][i] += min(dp[v][i], dp[v][!i]+1);
    if(i == a[u]-1) dp[u][i] = INF;
  }
}

int solve() {
  dfsDP(1);
  return min(dp[1][0], dp[1][1]);
}

int cat(int v) {
  a[v] = 1;
  return solve();
}

int dog(int v) {
  a[v] = 2;
  return solve();
}

int neighbor(int v) {
  a[v] = 0;
  return solve();
}

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