Submission #1018010

#	Time	Username	Problem	Language	Result	Execution time	Memory
1018010		n3rm1n	Friend (IOI14_friend)	C++17	46 / 100	21 ms	8284 KiB

friend

#include <bits/stdc++.h>
#define endl '\n'
#include "friend.h"
using namespace std;
long long ans = 0;
long long are[1005][1005], c[1005];
long long N, used[1005];
void check()
{
    vector < int > g;
    long long all = 0;
    for (int i = 0; i < N; ++ i)
    {
        if(used[i])
        {
            g.push_back(i);
            all += c[i];
        }
    }
    for (int i = 0; i < g.size(); ++ i)
    {
        for (int j = i+1; j < g.size(); ++ j)
            if(are[g[i]][g[j]])return;

    }
    ans = max(ans, all);
}
void gen(int pos)
{
    if(pos == N)
    {
        check();
        return;
    }
    used[pos] = 0;
    gen(pos+1);
    used[pos] = 1;
    gen(pos+1);
}
int cntp[4];
vector < int > g[1005];
int visited[1005];
int dfs(int beg)
{
    visited[beg] = 1;
    int maxx = c[beg];
    int nb;
    for (int i = 0; i < g[beg].size(); ++ i)
    {
        nb = g[beg][i];
        if(!visited[nb])maxx = max(maxx, dfs(nb));
    }
    return maxx;
}
int result = 0, dp[1005][2];
void dfs_dp(int beg)
{
    visited[beg] = 1;
    dp[beg][0] = 0;
    dp[beg][1] = c[beg];

    int nb;
    for (int i = 0; i < g[beg].size(); ++ i)
    {
        nb = g[beg][i];
        if(!visited[nb])
        {
            dfs_dp(nb);
            dp[beg][0] += max(dp[nb][1], dp[nb][0]);
            dp[beg][1] += dp[nb][0];
        }
    }
    result = max(result, dp[beg][1]);
    result = max(result, dp[beg][0]);
}
int findSample(int n, int confidence[], int host[], int protocol[])
{
    N = n;
    for (int i = 0; i < n; ++ i)
        cntp[protocol[i]] ++;
    for (int i = 0; i < n; ++ i)
        c[i] = confidence[i];




    if(n <= 10)
    {
        c[0] = confidence[0];
        for (int i = 1; i < n; ++ i)
        {
            c[i] = confidence[i];
            if(protocol[i] == 0)
            {
                g[i].push_back(host[i]);
                g[host[i]].push_back(i);
                are[i][host[i]] = 1;
                are[host[i]][i] = 1;
            }
            else
            {
                for (int j = 0; j < n; ++ j)
                {
                    if(are[j][host[i]])
                    {
                        g[i].push_back(j);
                        g[j].push_back(i);
                        are[i][j] = 1;
                        are[j][i] = 1;
                    }
                }
                if(protocol[i] == 2)
                {
                    g[i].push_back(host[i]);
                    g[host[i]].push_back(i);
                    are[i][host[i]] = 1;
                    are[host[i]][i] = 1;
                }
            }
        }
        gen(0);
        return ans;
    }
    if(cntp[2] == n-1)
    {
        long long maxx = 0;
        for (int i = 0; i < n; ++ i)
        {
            maxx = max(maxx, 1LL * confidence[i]);
        }
        return maxx;
    }
    if(cntp[1] == n-1)
    {
        long long ans = 0;
        for (int i = 0; i < n; ++ i)
        {
            if(!visited[i])ans += dfs(i);
        }
        return ans;
    }

    c[0] = confidence[0];
        for (int i = 1; i < n; ++ i)
        {
            c[i] = confidence[i];
            if(protocol[i] == 0)
            {
                g[i].push_back(host[i]);
                g[host[i]].push_back(i);
                are[i][host[i]] = 1;
                are[host[i]][i] = 1;
            }

        }
    for (int i = 0; i < n; ++ i)
        if(!visited[i])dfs_dp(i);

    return result;
}

Compilation message (stderr)

friend.cpp: In function 'void check()':
friend.cpp:20:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   20 |     for (int i = 0; i < g.size(); ++ i)
      |                     ~~^~~~~~~~~~
friend.cpp:22:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |         for (int j = i+1; j < g.size(); ++ j)
      |                           ~~^~~~~~~~~~
friend.cpp: In function 'int dfs(int)':
friend.cpp:48:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |     for (int i = 0; i < g[beg].size(); ++ i)
      |                     ~~^~~~~~~~~~~~~~~
friend.cpp: In function 'void dfs_dp(int)':
friend.cpp:63:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   63 |     for (int i = 0; i < g[beg].size(); ++ i)
      |                     ~~^~~~~~~~~~~~~~~

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