Submission #218626

#	Time	Username	Problem	Language	Result	Execution time	Memory
218626		MKopchev	Political Development (BOI17_politicaldevelopment)	C++14	100 / 100	545 ms	28932 KiB

politicaldevelopment

#include<bits/stdc++.h>
using namespace std;
const int nmax=5e4+42,kmax=20;
int n,k;

set<int> adj[nmax];

priority_queue< pair<int/*size*/,int/*node*/> > pq;

int output;

int active[kmax],pointer=0;

int bitmasks[nmax];

void solve(int node)
{
    active[0]=node;
    pointer=1;

    for(auto k:adj[node])
    {
        active[pointer]=k;
        pointer++;
    }

    for(int i=0;i<pointer;i++)
        bitmasks[i]=0;

    for(int i=0;i<pointer;i++)
        for(int j=0;j<pointer;j++)
        {
            if(i==j||adj[active[i]].count(active[j]))
                bitmasks[i]+=(1<<j);
        }
    /*
    cout<<"active: ";for(int i=0;i<pointer;i++)cout<<active[i]<<" ";cout<<endl;
    cout<<"masks: ";for(int i=0;i<pointer;i++)cout<<bitmasks[i]<<" ";cout<<endl;
    */

    for(int to_test=0;to_test<(1<<pointer);to_test++)
    {
        int in=0;
        for(int j=0;j<pointer;j++)
            if((to_test&(1<<j)))
            {
                if((bitmasks[j]&to_test)!=to_test)in=-1e9;
                else in++;
            }
        output=max(output,in);
    }
}
int main()
{
    scanf("%i%i",&n,&k);
    for(int i=0;i<n;i++)
    {
        int sz,node;
        scanf("%i",&sz);
        for(int j=1;j<=sz;j++)
        {
            scanf("%i",&node);
            adj[i].insert(node);
            adj[node].insert(i);
        }
    }

    for(int i=0;i<n;i++)
        pq.push({-adj[i].size(),i});

    for(int turn=0;turn<n;turn++)
    {
        while(adj[pq.top().second].size()!=-pq.top().first)pq.pop();//incorrect size

        int current=pq.top().second;
        pq.pop();

        //cout<<"current= "<<current<<endl;

        solve(current);

        for(auto k:adj[current])
        {
            adj[k].erase(current);
            pq.push({-adj[k].size(),k});
        }
        adj[current]={};
    }

    printf("%i\n",output);
    return 0;
}

Compilation message (stderr)

politicaldevelopment.cpp: In function 'int main()':
politicaldevelopment.cpp:73:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         while(adj[pq.top().second].size()!=-pq.top().first)pq.pop();//incorrect size
               ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
politicaldevelopment.cpp:55:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%i%i",&n,&k);
     ~~~~~^~~~~~~~~~~~~~
politicaldevelopment.cpp:59:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%i",&sz);
         ~~~~~^~~~~~~~~~
politicaldevelopment.cpp:62:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%i",&node);
             ~~~~~^~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 23 / 23
• Subtask 4: 38 / 38
• Subtask 5: 23 / 23