Submission #1017977

#	Time	Username	Problem	Language	Result	Execution time	Memory
1017977		serkanrashid	Friend (IOI14_friend)	C++14	27 / 100	16 ms	4456 KiB

friend

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

using namespace std;

const int maxn = 1024;

vector<int>g[maxn];
int con[maxn];
int used[maxn];
int sum[3];

void dfs(int beg)
{
    for(int nb : g[beg])
    {
        if(used[nb]) continue;
        used[nb] = 3-used[beg];
        sum[used[nb]] += con[nb];
        dfs(nb);
    }
}

int findSample(int n, int confidence[], int host[], int protocol[])
{
    for(int i = 0; i < n; i++) con[i] = confidence[i];

    bool f3 = true;
    for(int i = 1; i < n; i++)
    {
        if(protocol[i]!=2) f3 = false;
        if(protocol[i]==0)
        {
            g[host[i]].push_back(i);
            g[i].push_back(host[i]);
        }
        if(protocol[i]==1)
        {
            for(int nb : g[host[i]])
            {
                g[nb].push_back(i);
                g[i].push_back(nb);
            }
        }
        if(protocol[i]==2)
        {
            for(int nb : g[host[i]])
            {
                g[nb].push_back(i);
                g[i].push_back(nb);
            }
            g[host[i]].push_back(i);
            g[i].push_back(host[i]);
        }
    }

    if(f3)
    {
        int ans = 0;
        for(int i = 0; i < n; i++) if(con[i]>ans) ans = con[i];
        return ans;
    }
    if(n<=10)
    {
        int ans = 0;
        for(int mask = 1; mask < (1<<n); mask++)
        {
            int ch = 0;
            for(int j = 0; j < n; j++) if(mask&(1<<j)) ch += confidence[j];
            bool f = true;
            for(int j = 0; j < n; j++)
            {
                if((mask&(1<<j))==0) continue;
                for(int nb : g[j]) if(mask&(1<<nb)) f = false;
            }
            if(f) ans = max(ans,ch);
        }
        return ans;
    }


    int ans = 0;
    for(int i = 0; i < n; i++)
    {
        if(used[i]) continue;
        ans += max(sum[1],sum[2]);
        sum[1] = sum[2] = 0;
        sum[1] = con[i];
        used[i] = 1;
        dfs(i);
    }
    ans += max(sum[1],sum[2]);
    return ans;
}

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