Submission #111956

#	Time	Username	Problem	Language	Result	Execution time	Memory
111956		luciocf	Friend (IOI14_friend)	C++14	16 / 100	3 ms	384 KiB

friend

#include <bits/stdc++.h>
#include "friend.h"
 
using namespace std;
 
const int maxn = 1e3+10;

// ------- MATCHING --------
int match[maxn];

bool mark[maxn];
// -------------------------

int c[maxn];
 
int dp[maxn][2];
 
bool connected[maxn][maxn];
 
vector<int> grafo[maxn];
 
int dfs(int u, int p, bool is)
{
	if (grafo[u].size() == 1 && u != 0)
	{
		if (is) return c[u];
		return 0;
	}
	if (dp[u][is] != -1) return dp[u][is];
 
	int aux = 0;
	if (is) aux = c[u];
 
	for (auto v: grafo[u])
	{
		if (v == p) continue;
 
		if (is) aux += dfs(v, u, 0);
		else aux += max(dfs(v, u, 0), dfs(v, u, 1));
	}
 
	return dp[u][is] = aux;
}

bool dfs_match(int u)
{
	if (mark[u]) return false;

    mark[u] = true;
    for (auto v: grafo[u])
    {
        if (match[v] == -1 || dfs_match(match[v]))
        {
            match[v] = u;
            return true;
        }
    }

    return false;
}

int get_match(int n)
{
    memset(match, -1, sizeof match);

    int ans = 0;
    for (int i = 0; i < n; i++)
    {
        memset(mark, 0, sizeof mark);

        if (dfs_match(i)) ans++;
    }

    return ans;
}
 
int findSample(int n, int confidence[], int host[], int protocol[])
{
	bool sub5 = 1;
	for (int i = 0; i < n; i++)
	{
		c[i] = confidence[i];

		if (c[i] != 1 || (i > 0 && protocol[i] == 2)) sub5 = 0;
	}

	if (sub5)
	{
		dfs_match(0);

		return n-get_match(n);
	}
 
	if (n > 10)
	{
		if (protocol[1] == 2)
		{
			int mx = 0;
			for (int i = 0; i < n; i++)
				mx = max(mx, c[i]);
			return mx;
		}
		else if (protocol[1] == 1)
		{
			int s = 0;
			for (int i = 0; i < n; i++)
				s += c[i];
 
			return s;
		}
		else
		{
			memset(dp, -1, sizeof dp);
 
			for (int i = 1; i < n; i++)
				grafo[i].push_back(host[i]), grafo[host[i]].push_back(i);
 
			return max(dfs(0, -1, 0), dfs(0, -1, 1));
		}
	}
 
	for (int i = 1; i < n; i++)
	{
		int h = host[i];
 
		if (protocol[i] == 0)
		{
			connected[i][h] = connected[h][i] = 1;
		}
		else if (protocol[i] == 1)
		{
			for (int j = 0; j < n; j++)
				if (connected[h][j])
					connected[i][j] = connected[j][i] = 1;
		}
		else
		{
			for (int j = 0; j < n; j++)
				if (connected[h][j])
					connected[i][j] = connected[j][i] = 1;
			connected[i][h] = connected[h][i] = 1;
		}
	}
 
	int ans = 0;
 
	for (int mask = 0; mask < (1<<n); mask++)
	{
		bool ok = 1;
		for (int i = 0; i < n; i++)
			for (int j = 0; j < n; j++)
				if (connected[i][j] && mask&(1<<i) && mask&(1<<j))
					ok = 0;
 
		if (ok)
		{
			int aux = 0;
			for (int i = 0; i < n; i++)
				if (mask&(1<<i))
					aux += c[i];
			ans = max(ans, aux);
		}
	}
 
	return ans;
}

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