Submission #105237

#	Time	Username	Problem	Language	Result	Execution time	Memory
105237		TuGSGeReL	Friend (IOI14_friend)	C++14	27 / 100	54 ms	1528 KiB

friend

#include "friend.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;

#define ll long long
#define mp make_pair
#define pub push_back
#define pob pop_back()
#define ss second
#define ff first
#define mt make_tuple
#define pof pop_front()
#define fbo find_by_order
#define ook order_of_key

typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
using pll = pair <ll, ll>;
using pii = pair <int, int>;

int used[1001], pre[3], dp[1001][2];
vector <int> edg[1001];

int solve1(int n, int confidence[], int host[], int protocol[])
{
	
	int ans = 0;
	
	for (int i = 1; i < n; i++)
	{
		if ( !protocol[i] )
		{
			edg[i].pub(host[i]);
			edg[host[i]].pub(i);
		} else if ( protocol[i] == 1 )
		{
			for (int j = 0; j < edg[host[i]].size(); j++)
			{
				edg[edg[host[i]][j]].pub(i);
				edg[i].pub(edg[host[i]][j]);
			}
		} else {
			for (int j = 0; j < edg[host[i]].size(); j++)
			{
				edg[i].pub(edg[host[i]][j]);
				edg[edg[host[i]][j]].pub(i);
			}

			edg[i].pub(host[i]);
			edg[host[i]].pub(i);
		}
	}
	
	for (int i = 0; i < (1 << n); i++)
	{
		memset(used, 0, sizeof used);
		bool boo = 0;
		int res = 0;

		for (int j = 0; j < n; j++)
		{
			if ( i & (1 << j) )
			{
				for ( auto x : edg[j] )
					if ( used[x] )
						boo = 1;

				res += confidence[j];
				used[j] = 1;
			}
		}

		if ( !boo )
			ans = max(ans, res);
	}
	
	return ans;
}

void dfs(int u, int par)
{
	for (auto x : edg[u])
		if ( x != par )
			dfs(x, u);
	
	if ( par != -1 )
	{
		dp[par][0] += max(dp[u][1], dp[u][0]);
		dp[par][1] += dp[u][0];
	}
}

int findSample(int n,int confidence[],int host[],int protocol[]){
	
	if ( n <= 10 )
		return solve1(n, confidence, host, protocol);
	
	for (int i = 1; i < n; i++)
		pre[protocol[i]]++;
	
	if ( pre[1] == n - 1 )
	{
		int ans = 0;
		
		for (int i = 0; i < n; i++)
			ans += confidence[i];
		
		return ans;
	}
	
	if ( pre[2] == n - 1 )
	{
		int ans = 0;
		
		for (int i = 0; i < n; i++)
			ans = max(ans, confidence[i]);
		
		return ans;
	}
	
	if ( pre[0] == n - 1 )
	{
		for (int i = 1; i < n; i++)
		{
			edg[host[i]].pub(i);
			edg[i].pub(host[i]);
		}
		
		dfs(0, -1);
		
		return max(dp[0][0], dp[0][1]);
	}
}

Compilation message (stderr)

friend.cpp: In function 'int solve1(int, int*, int*, int*)':
friend.cpp:39:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int j = 0; j < edg[host[i]].size(); j++)
                    ~~^~~~~~~~~~~~~~~~~~~~~
friend.cpp:45:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int j = 0; j < edg[host[i]].size(); j++)
                    ~~^~~~~~~~~~~~~~~~~~~~~
friend.cpp: In function 'int findSample(int, int*, int*, int*)':
friend.cpp:135:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

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