Submission #431896

#	Time	Username	Problem	Language	Result	Execution time	Memory
431896		cfalas	Friend (IOI14_friend)	C++14	8 / 100	11 ms	408 KiB

friend

#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
typedef pair<int, int> ii;
#define FORi(i,a,b) for(int i=(int)a;i<(int)b;i++)
#define FOR(i,n) FORi(i,0,n)
#include "friend.h"
typedef vector<int> vi;
// Find out best sample

vector<vi> adj;
vi vis;

int a[10000];
int dp[100000][2];
int dfs(int s, int p=-1, int cp=0){
	if(dp[s][cp]) return dp[s][cp];
	vis[s] = true;
	int ans1 = 0;
	int ans2=0;
	if(cp){
		for(auto v : adj[s]) if(v!=p) ans1+=dfs(v, s, 0);
	}
	else{
		for(auto v : adj[s]) if(v!=p) ans1+=dfs(v, s, 0);
		ans2 = a[s];
		for(auto v : adj[s]) if(v!=p) ans2+=dfs(v, s, 1);
	}
	//cout<<s<<" "<<cp<<" "<<ans1<<" "<<ans2<<endl;
	dp[s][cp] = max(ans1, ans2);
	return max(ans1, ans2);
}

int ans1=0, ans2=0;

void color(int s, int p=-1, int pc=0){
	if(pc) ans1++;
	else ans2++;
	for(auto v : adj[s]) if(v!=p) color(v, s);
}

int findSample(int n,int confidence[],int host[],int protocol[]){
	int ans=0;
	bool sub1=1, sub2=1;
	FORi(i,1,n) if(protocol[i]!=1) sub1 = false;
	FORi(i,1,n) if(host[i]!=1) sub2 = false;
	if(sub1) FOR(i,n) ans+=confidence[i];
	else if(sub2) FOR(i,n) ans=max(ans, confidence[i]);
	else{
		int tot=0;
		FOR(i,n) a[i] = confidence[i], tot+=a[i];
		adj.assign(n+1, vi());
		vis.assign(n+1, false);
		FORi(i,1,n){
			adj[host[i]].push_back(i);
			adj[i].push_back(host[i]);
		}
		if(tot>n){
			FOR(i,n) if(!vis[i]) ans+=dfs(i);
		}
		else{
			FOR(i,n){
				if(!vis[i]){
					ans1 = 0;
					ans2 = 0;
					color(i);
					ans+= max(ans1,ans2);
				}
			}
		}
	}
	return ans;
}

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