Submission #586247

#	Time	Username	Problem	Language	Result	Execution time	Memory
586247		krit3379	Friend (IOI14_friend)	C++17	46 / 100	35 ms	4556 KiB

friend

#include<bits/stdc++.h>
#include"friend.h"
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define N 100005

int dp[N][2],col[N],cnt,cou,sum,ans;
bool f[3];
vector<int> g[N];

void dfs(int s,int f,int confidence[]){
    for(auto x:g[s]){
        if(x==f)continue;
        dfs(x,s,confidence);
        dp[s][1]+=dp[x][0];
        dp[s][0]+=max(dp[x][0],dp[x][1]);
    }
    dp[s][1]+=confidence[s];
    ans=max({ans,dp[s][0],dp[s][1]});
}

void bi(int s,int c){
    if(col[s]!=-1)return ;
    cnt++;
    cou+=c;
    col[s]=c;
    for(auto x:g[s])bi(x,1-c);
}

int findSample(int n,int confidence[],int host[],int protocol[]){
    int i,j,k;
    if(n<=10){
        bitset<15> vis[N];
        for(i=0;i<=n;i++)vis[i]=0;
        for(i=1;i<n;i++){
            if(protocol[i])for(j=0;j<n;j++)if(vis[host[i]][j])vis[i][j]=vis[j][i]=true;
            if(protocol[i]!=1)vis[i][host[i]]=vis[host[i]][i]=true;
        }
        for(i=0;i<(1<<n);i++){
            sum=0;
            for(j=0;j<n;j++){
                if(i&(1<<j)){
                    for(k=0;k<n;k++)if(vis[j][k]&&(i&(1<<k)))break;
                    if(k!=n)break;
                    sum+=confidence[j];
                }
            }
            if(j==n)ans=max(ans,sum);
        }
    }
    else if(n<=1000){
        for(i=1;i<n;i++)f[protocol[i]]=true;
        if(!f[0]&&f[1]&&!f[2])for(i=0;i<n;i++)ans+=confidence[i];
        else if(!f[0]&&!f[1]&&f[2])for(i=0;i<n;i++)ans=max(ans,confidence[i]);
        else if(f[0]&&!f[1]&&!f[2]){
            for(i=1;i<n;i++)g[i].push_back(host[i]),g[host[i]].push_back(i);
            dfs(0,-1,confidence);
        }
        else{
            for(i=1;i<n;i++){
                if(protocol[i]==0)g[i].push_back(host[i]),g[host[i]].push_back(i);
                else for(auto x:g[host[i]])g[i].push_back(x),g[x].push_back(i);
            }
            for(i=0;i<n;i++)col[i]=-1;
            for(i=0;i<n;i++)if(col[i]==-1)cnt=cou=0,bi(i,0),ans+=max(cou,cnt-cou);
        }
    }
    else{

    }
    return ans;
}

• Subtask 1: 11 / 11
• Subtask 2: 8 / 8
• Subtask 3: 8 / 8
• Subtask 4: 19 / 19
• Subtask 5: 0 / 23
• Subtask 6: 0 / 31