Submission #232112

#	Time	Username	Problem	Language	Result	Execution time	Memory
232112		spdskatr	Friend (IOI14_friend)	C++14	46 / 100	37 ms	2808 KiB

friend

#include "friend.h"
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <utility>
#include <cassert>

using namespace std;
int adj[15][15], seen[1005], dp[1005][2], conf[1005];
vector<int> graph[1005];

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

// Find out best sample
int findSample(int n,int confidence[],int host[],int protocol[]){
	int st2 = 1, st3 = 1, st4 = 1;
	for (int i = 0; i < n; i++) conf[i] = confidence[i];
	for (int i = 1; i < n; i++) {
		if (protocol[i] == 0) st2 = st3 = 0;
		else if (protocol[i] == 1) st3 = st4 = 0;
		else st2 = st4 = 0;
	}
	if (st2) {
		int ans = 0;
		for (int i = 0; i < n; i++) ans += confidence[i];
		return ans;
	} else if (st3) {
		int ans = 0;
		for (int i = 0; i < n; i++) ans = max(ans, confidence[i]);
		return ans;
	} else if (st4) {
		for (int i = 1; i < n; i++) {
			graph[host[i]].push_back(i);
			graph[i].push_back(host[i]);
		}
		dfs(0, 0);
		return dp[0][0];
	} else if (n <= 10) {
		int ans = 0;
		for (int i = 1; i < n; i++) {
			if (protocol[i] == 0) {
				adj[i][host[i]] = adj[host[i]][i] = 1;
			} else if (protocol[i] == 1) {
				for (int v = 0; v < n; v++) if (adj[host[i]][v])
					adj[i][v] = adj[v][i] = 1;
			} else {
				adj[i][host[i]] = adj[host[i]][i] = 1;
				for (int v = 0; v < n; v++) if (adj[host[i]][v])
					adj[i][v] = adj[v][i] = 1;
			}
		}
		for (int s = 0; s < (1 << n); s++) {
			int cooked = 0;
			for (int a = 0; a < n; a++) for (int b = a+1; b < n; b++) {
				if (((s >> a) & (s >> b) & 1) && adj[a][b]) cooked = 1;
			}
			if (!cooked) {
				int res = 0;
				for (int i = 0; i < n; i++) if ((s >> i) & 1) res += conf[i];
				ans = max(ans, res);
			}
		}
		return ans;
	} else assert(false);
}

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