Submission #404177

#	Time	Username	Problem	Language	Result	Execution time	Memory
404177		bigg	Friend (IOI14_friend)	C++14	46 / 100	31 ms	4972 KiB

friend

#include "friend.h"
#include<bits/stdc++.h>
using namespace std;
// Find out best sample
const int MAXN = 1e5 + 10;
vector<int> grafo[MAXN];
int dp[MAXN][5], v[MAXN], comp[MAXN], maxc[MAXN];
int mat[15][15];
void dfsc(int x, int p, int c){
	comp[x] = c;
	for(int v : grafo[x]){
		if(v == p) continue;
		dfsc(v, x, c);
	}
}

void dfs(int x, int p){
	dp[x][0] = 0, dp[x][1] = v[x];
	for(int v : grafo[x]){
		if(v == p) continue;
		dfs(v, x);
		dp[x][0] += max(dp[v][0], dp[v][1]);
		dp[x][1] += dp[v][0];
	}
}

int findSample(int n,int confidence[],int host[],int protocol[]){

	int ans= 0;
	if(n <= 10){
		for(int i = 1; i < n; i++){
			if(protocol[i] == 0){
				grafo[i].push_back(host[i]);
				grafo[host[i]].push_back(i);
				mat[i][host[i]] = mat[host[i]][i] = 1;
			}
			if(protocol[i] >= 1){
				for(int v : grafo[host[i]]){
					grafo[i].push_back(v);
					grafo[v].push_back(i);
					mat[i][v] = mat[v][i] = 1;
				}
				if(protocol[i] == 2){
					grafo[i].push_back(host[i]);
					grafo[host[i]].push_back(i);
					mat[i][host[i]] = mat[host[i]][i] = 1;
				}
			}
		}
		for(int i = 0; i < (1<<n); i++){
			int aq = 0;
			bool ok = 0;
			for(int v1 = 0; v1 < n; v1++){
				for(int v2 = v1 + 1; v2 < n; v2++){
					if((1<<v1) & i && (1<<v2) & i && mat[v1][v2]) ok = 1;
				}
			}
			if(ok) continue;
			for(int j = 0; j < n; j++){

				if((1<<j) & i) aq += confidence[j];
				
			}
			
			ans = max(ans, aq);
		}
		return ans;
	}

	if(protocol[1] == 1){
		for(int i = 0; i < n; i++) ans += confidence[i];
		return ans;
	}
	if(protocol[1] == 2){
		for(int i = 0; i < n; i++) ans = max(ans, confidence[i]);
		return ans;
	}
	for(int i = 0; i < n; i++) v[i] = confidence[i];
	for(int i = 1; i < n; i++){
		grafo[host[i]].push_back(i);
		grafo[i].push_back(host[i]);
	}
	int c = 0;
	for(int i = 0; i < n; i++){
		if(!comp[i]){
			dfsc(i,i, ++c);
		}
	}
	for(int i = 0; i < n; i++){
		dfs(i, i);

		maxc[comp[i]] = max(maxc[comp[i]], dp[i][1]);
	}
	for(int i = 1; i <= c; i++) ans += maxc[i];
	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