Submission #242404

#	Time	Username	Problem	Language	Result	Execution time	Memory
242404		joseacaz	Friend (IOI14_friend)	C++17	27 / 100	48 ms	65540 KiB

friend

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

#define pb push_back

using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 1005;
int prot[3], on[MAXN], DP[MAXN][2], vis[MAXN][2];
int aux, ans;
vi Graph[MAXN];

int solve(int node, int f, int confidence[])
{
    if(vis[node][f])
        return DP[node][f];

    int res1 = 0, res2 = 0;
    for(auto i : Graph[node])
    {
        res1 += solve(node, 1, confidence);
        res2 += solve(node, 0, confidence);
    }
    
    vis[node][f] = 1;
    if(f)
        return DP[node][f] = max(res1, res2 + confidence[node]);
    else
        return DP[node][f] = res1;
}

// Find out best sample
int findSample(int N, int confidence[], int host[], int protocol[])
{
    if(N > 1000)
        return 0;

    for(int i = 1; i < N; i++)
        prot[protocol[i]]++;
    
    //S1
    if(N <= 10)
    {
        for(int i = 1; i < N; i++)
        {
            if(protocol[i] == 0)
            {
                Graph[host[i]].pb(i);
                Graph[i].pb(host[i]);
            }
            else if(protocol[i] == 1)
            {
                for(auto v : Graph[host[i]])
                {
                    Graph[v].pb(i);
                    Graph[i].pb(v);
                }
            }
            else if(protocol[i] == 2)
            {
                for(auto v : Graph[host[i]])
                {
                    Graph[v].pb(i);
                    Graph[i].pb(v);
                }
                Graph[host[i]].pb(i);
                Graph[i].pb(host[i]);
            }
        }
        for(int i = 0; i < (1 << N); i++)
        {
            aux = 0;
            for(int j = 0; j < N; j++)
            {
                on[j] = 0;
                if(i & (1 << j))
                {
                    on[j] = 1;
                    aux += confidence[j];
                }
            }
            
            bool ind = 1;
            for(int node = 0; node < N; node++)
                if(on[node])
                    for(auto j : Graph[node])
                        if(on[j])
                            ind = 0;
            if(!ind)
                continue;
            ans = max(ans, aux);
        }
    }
    //S2
    else if(prot[1] == N - 1)
    {
        for(int i = 0; i < N; i++)
            ans += confidence[i];
    }
    //S3
    else if(prot[2] == N - 1)
    {
        for(int i = 0; i < N; i++)
            ans = max(ans, confidence[i]);
    }
    //S4
    else if(prot[0] == N - 1)
    {
        for(int i = 1; i < N; i++)
        {
            if(protocol[i] == 0)
            {
                Graph[host[i]].pb(i);
                Graph[i].pb(host[i]);
            }
        }
        ans = solve(0, 1, confidence);
    }
    return ans;
}

Compilation message (stderr)

friend.cpp: In function 'int solve(int, int, int*)':
friend.cpp:24:14: warning: unused variable 'i' [-Wunused-variable]
     for(auto i : Graph[node])
              ^

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