Submission #939953

#	Time	Username	Problem	Language	Result	Execution time	Memory
939953		sleepntsheep	Cats or Dogs (JOI18_catdog)	C++17	38 / 100	18 ms	4188 KiB

catdog

#include "catdog.h"
#include<stdio.h>
#include<algorithm>


#define N 2000

int shin[N],dp[N][2], e[N][2],ne,h[N];

void link(int u,int v)
{
    e[++ne][0]=v,e[ne][1]=h[u],h[u]=ne;
}

void dfs(int u,int p)
{
    dp[u][0]=dp[u][1]=0;
    for(int v,j=h[u];j;j=e[j][1])if((v=e[j][0])-p)
    {
        dfs(v,u);
        for(int k=0;k<2;++k)
            dp[u][k]+=std::min(dp[v][k],dp[v][k^1]+1);
    }
    if(shin[u])
    {
        dp[u][(shin[u]-1)^1]=1e9;
    }
}

void initialize(int n, std::vector<int> a, std::vector<int> b)
{
    for (int i=0;i<n-1;++i)link(a[i],b[i]),link(b[i],a[i]);
}

int cat(int u) {
    shin[u]=1;
    dfs(1,1);
    return std::min(dp[1][0],dp[1][1]);
}

int dog(int u) {
    shin[u]=2;
    dfs(1,1);
    return std::min(dp[1][0],dp[1][1]);
}

int neighbor(int u) {
    shin[u]=0;
    dfs(1,1);
    return std::min(dp[1][0],dp[1][1]);
}

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