Submission #114446

#	Time	Username	Problem	Language	Result	Execution time	Memory
114446		E869120	Friend (IOI14_friend)	C++14	27 / 100	5 ms	2816 KiB

friend

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

vector<int> G[100009]; int A[100009];
int dp[100009][2][2], ty[100009];

void dfs(int pos) {
	// 1 個目： 0 = 白, 1 = 黒　2 個目： 0 = すべて白、1 = 1 個以上黒
	for (int i = 0; i < G[pos].size(); i++) dfs(G[pos][i]);
	
	// dp[0][0] を求める
	for (int to : G[pos]) {
		if (ty[to] == 1 || ty[to] == 2) dp[pos][0][0] += max({dp[to][0][0], dp[to][1][0]});
		else dp[pos][0][0] += max({dp[to][0][0], dp[to][0][1], dp[to][1][0], dp[to][1][1]});
	}
	
	// dp[0][1] を求める
	for (int to : G[pos]) {
		if (ty[to] == 0 || ty[to] == 2) dp[pos][0][1] += max({dp[to][0][0], dp[to][0][1]});
		else dp[pos][0][1] += max({dp[to][0][0], dp[to][0][1], dp[to][1][0], dp[to][1][1]});
	}
	
	// dp[1][0] を求める
	if (ty[pos] == 0) {
		dp[pos][1][0] = A[pos];
		for (int to : G[pos]) {
			if (ty[to] == 2) dp[pos][1][0] += max({dp[to][0][0]});
			if (ty[to] == 1) dp[pos][1][0] += max({dp[to][0][0], dp[to][1][0]});
			if (ty[to] == 0) dp[pos][1][0] += max({dp[to][0][0], dp[to][0][1]});
		}
	}
	
	// dp[1][1] を求める
	dp[pos][1][1] = A[pos];
	for (int to : G[pos]) {
		if (ty[to] == 0 || ty[to] == 2) dp[pos][1][1] += max({dp[to][0][0], dp[to][0][1]});
		else dp[pos][1][1] += max({dp[to][0][0], dp[to][0][1], dp[to][1][0], dp[to][1][1]});
	}
}

int findSample(int n,int confidence[],int host[],int protocol[]){
	for (int i = 0; i < n; i++) A[i] = confidence[i];
	for (int i = 1; i < n; i++) ty[i] = protocol[i];
	for (int i = 1; i < n; i++) G[host[i]].push_back(i);
	dfs(0);
	//for (int i = 0; i < n; i++) cout << dp[i][0][0] << " " << dp[i][0][1] << " "<< dp[i][0][2] << " " << dp[i][0][3] << endl;
	return max({dp[0][0][0], dp[0][0][1], dp[0][1][0], dp[0][1][1]});
}

Compilation message (stderr)

friend.cpp: In function 'void dfs(int)':
friend.cpp:10:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < G[pos].size(); i++) dfs(G[pos][i]);
                  ~~^~~~~~~~~~~~~~~

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