Submission #296389

#	Time	Username	Problem	Language	Result	Execution time	Memory
296389		arayi	Friend (IOI14_friend)	C++17	46 / 100	38 ms	4352 KiB

friend

#include <bits/stdc++.h>
#include "friend.h"
#define ad push_back
using namespace std;

const int N = 1010;
int n;
vector <int> g[N];
bool col[20][20];
int dp[N][2];
int sz[N];
bool cl[N];
int findmn()
{
    int mn = n, ret = -1;
    for (int i = 0; i < n; i++)
    {
        if(cl[i]) continue;
        if(sz[i] < mn) mn = sz[i], ret = i;
    }
    return ret;
}
void dfs(int v, int par)
{
    int sum = 0, sm = 0;
    for(auto p : g[v])
    {
        if(p == par) continue;
        dfs(p, v);
        sum += dp[p][0];
        sm += max(dp[p][1], dp[p][0]);
    }
    dp[v][0] = sm;
    dp[v][1] += sum;
}
int findSample(int n1,int c[],int host[],int pr[])
{
    n = n1;
    bool mk, erk, erq;
    mk=erk=erq=0;
	for (int i = 1; i < n; i++)
	{
	    if(pr[i] == 0)
        {
            g[host[i]].ad(i);
            g[i].ad(host[i]);
            mk = 1;
        }
        else if(pr[i] == 1)
        {
            for(auto p : g[host[i]]) g[p].ad(i), g[i].ad(p);
            erk = 1;
        }
        else
        {
            for(auto p : g[host[i]]) g[p].ad(i), g[i].ad(p);
            g[host[i]].ad(i);
            g[i].ad(host[i]);
            erq = 1;
        }
	}
	if(n <= 10)
    {
        for (int i = 0; i < n; i++)
            for(auto p : g[i]) col[i][p] = 1;//, cout << i << " " << p << endl;
        int pat = 0;
        for(int x = 0; x < (1 << n); ++x)
        {
            int sum = 0;
            vector <int> sm;
            for (int i = 0; i < n; i++)
                if(x & (1 << i)) sum += c[i], sm.ad(i);
            bool bl = 0;
            for(auto p : sm)
                for(auto p1 : sm) if(col[p][p1]) bl = true;
            if(!bl) pat = max(pat, sum);
        }
        return pat;
    }
    if(!mk && erk && !erq)
    {
        int pat = 0;
        for (int i = 0; i < n; i++)
            pat += c[i];
        return pat;
    }
    if(!mk && !erk && erq)
    {
        int pat = 0;
        for (int i = 0; i < n; i++)
            pat = max(pat, c[i]);
        return pat;
    }
    if(mk && !erk && !erq)
    {
        for (int i = 0; i < n; i++) dp[i][1] = c[i];
        dfs(0, 0);
        return max(dp[0][0], dp[0][1]);
    }
    else
    {
        int pat = 0;
        while(1)
        {
            int sm = findmn();
            if(sm == -1) break;
            pat++;
            cl[sm] = 1;
            for(auto p : g[sm])
            {
                cl[p] = 1;
                for(auto p1 : g[p]) sz[p1]--;
            }
        }
        return pat;
    }
}

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