Submission #1277292

#	Time	Username	Problem	Language	Result	Execution time	Memory
1277292		Johann	Friend (IOI14_friend)	C++20	19 / 100	2 ms	584 KiB

friend

#include "friend.h"

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

#define sz(x) (int)(x.size())

typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<pii> vpii;

void dfs(int v, int p, vvi &adj, vvi &mxt, const int C[])
{
	mxt[v][1] = C[v];
	for (int u : adj[v])
	{
		if (u == p)
			continue;
		dfs(u, v, adj, mxt, C);
		mxt[v][0] += max(mxt[u][0], mxt[u][1]);
		mxt[v][1] += mxt[u][0];
	}
}

// Find out best sample
int findSample(int n, int confidence[], int host[], int protocol[])
{
	vi C(n);
	// copy(confidence, confidence + n, C.begin());
	// subtaks 2: only my friends are your friends -> independent set!
	// int sum = accumulate(confidence, confidence + n, 0);
	// subtask 3: only we are your friends -> complete graph
	// int maxi = *max_element(confidence, confidence + n);
	// subtask 4: only I am your friend -> tree dp
	vvi adj(n);
	for (int t = 1; t < n; ++t)
	{
		adj[host[t]].push_back(t);
		adj[t].push_back(host[t]);
	}
	vvi max_subtree(n, vi(2, 0)); // max subtree without and with corresponding root
	dfs(0, 0, adj, max_subtree, confidence);
	return max(max_subtree[0][0], max_subtree[0][1]);

	/*

	vvi dp(n, vi(2, 0));
	dp[0][0] = confidence[0]; // best res with zero
	dp[0][1] = 0;			  // best rest without 0
	ll bestRes = confidence[0];

	for (int t = 1; t < n; ++t)
	{
	}

	return sum;
	*/
}

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