Submission #298093

#	Time	Username	Problem	Language	Result	Execution time	Memory
298093		mieszko11b	Friend (IOI14_friend)	C++14	46 / 100	35 ms	1528 KiB

friend

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

using namespace std;

bool subtask[6];
int G[20][20];

void add_edge(int a, int b) {
	G[a][b] = 1;
	G[b][a] = 1;
	//~ cout << a << " " << b << endl;
}

vector<int> c;
int dp[1007][2];
vector<int> ch[1007];

void dfs(int w) {
	dp[w][1] = c[w];
	for(int u : ch[w]) {
		dfs(u);
		dp[w][0] += max(dp[u][0], dp[u][1]);
		dp[w][1] += dp[u][0];
	}
}

int findSample(int n,int confidence[],int host[],int protocol[]) {
	for(int i = 1 ; i<= 5 ; i++)
		subtask[i] = 1;
	if(n > 10)
		subtask[1] = 0;
		
	for(int i = 1 ; i < n ; i++) {
		if(protocol[i] == 0)
			subtask[2] = subtask[3] = 0;
		if(protocol[i] == 1)
			subtask[3] = subtask[4] = 0;
		if(protocol[i] == 2)
			subtask[2] = subtask[4] = subtask[5] = 0;
	}
	
	if(subtask[1]) {
		for(int i = 1 ; i < n ; i++) {
			if(protocol[i] == 0) {
				add_edge(i, host[i]);
			} else if(protocol[i] == 1) {
				for(int x = 0 ; x < n ; x++)
					if(G[host[i]][x])
						add_edge(x, i);
			} else {
				for(int x = 0 ; x < n ; x++)
					if(G[host[i]][x])
						add_edge(x, i);
				add_edge(i, host[i]);
			}
		}
		
		int res = 0;
		for(int mask = 0 ; mask < (1 << n) ; mask++) {
			int sum = 0;
			bool ok = true;
			for(int i = 0 ; i < n ; i++) {
				if(mask & (1 << i)) {
					sum += confidence[i];
					for(int j = i + 1 ; j < n ; j++) {
						if(mask & (1 << j)) {
							if(G[i][j])
								ok = false;
						}
					}
				}
			}
			if(ok)
				res = max(res, sum);
		}
		
		return res;
	}
	
	if(subtask[2]) {
		int sum = 0;
		for(int i = 0 ; i < n ; i++)
			sum += confidence[i];
		return sum;
	}
	
	if(subtask[3]) {
		int maxv = 0;
		for(int i = 0 ; i < n ; i++)
			maxv = max(maxv, confidence[i]);
		return maxv;
	}
	
	if(subtask[4]) {
		c.resize(n);
		for(int i = 0 ; i < n ; i++)
			c[i] = confidence[i];
		for(int i = 1 ; i < n ; i++)
			ch[host[i]].push_back(i);
		dfs(0);
		return max(dp[0][0], dp[0][1]);
	}
	
	return 0;
}

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