Submission #1073981

#	Time	Username	Problem	Language	Result	Execution time	Memory
1073981		Malix	Friend (IOI14_friend)	C++14	11 / 100	116 ms	65536 KiB

friend

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

#define REP(a,b,c) for(int a=b;a<c;a++)
#define F first
#define S second
#define PB push_back

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

vii a;
int n;

int brute(int confidence[]){
	int m=pow(2,n);
	int ans=0;
	REP(i,0,n)sort(a[i].begin(),a[i].end());
	REP(i,1,m){
		int k=0;
		set<int> st;
		REP(j,0,n){
			if(i&(1<<j))st.insert(j);
		}
		bool flag=1;
		for(auto u:st){
			for(auto v:a[u]){
				if(st.count(v)!=0)flag=0;
			}
		}
		for(auto u:st)k+=confidence[u];
		if(flag)ans=max(ans,k);
	}
	return ans;
}

// Find out best sample
int findSample(int N,int confidence[],int host[],int protocol[]){
	n=N;
	bool flag=1;
	REP(i,1,n)if(protocol[i]!=1)flag=0;
	if(flag)return *max_element(confidence,confidence+n);
	a.resize(n);
	REP(i,1,n){
		int pos=host[i];
		if(protocol[i]==0||protocol[i]==2){
			a[pos].PB(i);
			a[i].PB(pos);
		}
		if(protocol[i]==1||protocol[i]==2){
			for(auto u:a[pos])if(u!=i){
				a[u].PB(i);
				a[i].PB(u);
			}
		}
	}
	if(n<=10)return brute(confidence);
	vi t(n,-1);
	t[0]=0;
	queue<pi> pq;
	pq.push({0,0});
	while(!pq.empty()){
		int x=pq.front().F;
		pq.pop();
		for(auto u:a[x])if(t[u]==-1){
			t[u]=1-t[x];
			pq.push({u,t[u]});
		}
	}
	int l=0,r=0;
	REP(i,0,n){
		if(t[i]==0)l+=confidence[i];
		else r+=confidence[i];
	}
	return max(l,r);
}

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