Submission #283172

#	Time	Username	Problem	Language	Result	Execution time	Memory
283172		MKopchev	Toy Train (IOI17_train)	C++14	11 / 100	1100 ms	3328 KiB

train

#include "train.h"
#include<bits/stdc++.h>
using namespace std;

const int nmax=1e4+42;

int nxt[nmax];

vector<int> adj[nmax],trav[nmax],adj_comp[nmax];

int n,owner[nmax],charge[nmax];

int rec(int node)//1-> A wins, 0-> B wins
{
    if(nxt[node]!=-1)
    {
        if(charge[node])return 1;

        int other=nxt[node];

        while(other!=node)
        {
            if(charge[other])return 1;

            other=nxt[other];
        }

        return 0;
    }

    for(auto k:adj[node])
    {
        nxt[node]=k;

        int mem=rec(k);

        nxt[node]=-1;

        if(mem==owner[node])return mem;
    }

    return !owner[node];
}

bool been[nmax];

stack<int> st;

void dfs(int node)
{
    if(been[node])return;

    been[node]=1;

    for(auto k:adj[node])
        dfs(k);

    st.push(node);
}

int pointer,comp[nmax];

int mem[nmax];

int charge_comp[nmax];

vector<int> seen={};

set< pair<int,int> > edges;

void dfs_trav(int node)
{
    if(comp[node])return;

    comp[node]=pointer;

    seen.push_back(node);

    //charge_comp[pointer]=charge_comp[pointer]|charge[node];

    for(auto k:trav[node])
        dfs_trav(k);
}

int win(int node)
{
    if(mem[node]!=-1)return mem[node];

    int ret=charge_comp[node];

    for(auto k:adj_comp[node])
        ret=ret|win(k);

    mem[node]=ret;

    return ret;
}

bool b_win[nmax];

bool test(int node)
{
    if(been[node])return 0;

    if(b_win[comp[node]])return 1;

    been[node]=1;

    for(auto k:adj[node])
        if(test(k))return 1;

    return 0;
}

std::vector<int> who_wins(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v)
{
    memset(mem,-1,sizeof(mem));

    memset(nxt,-1,sizeof(nxt));

    n=a.size();

    for(int i=0;i<a.size();i++)owner[i]=a[i];

    for(int i=0;i<r.size();i++)charge[i]=r[i];

    for(int i=0;i<u.size();i++)
        if(charge[u[i]]==0&&charge[v[i]]==0)
        {
            adj[u[i]].push_back(v[i]);
            trav[v[i]].push_back(u[i]);

            edges.insert({u[i],v[i]});
        }
    //B is owner of all
    for(int i=0;i<n;i++)
        if(been[i]==0)dfs(i);

    memset(been,0,sizeof(been));

    while(st.size())
    {
        seen={};

        int tp=st.top();

        //cout<<"tp= "<<tp<<endl;

        st.pop();

        if(been[tp])continue;

        pointer++;
        dfs_trav(tp);

        if(seen.size()>=2||(seen.size()==1&&edges.count({seen[0],seen[0]})))
        {
            b_win[pointer]=1;
        }
        //cout<<pointer<<" -> "<<b_win[pointer]<<endl;
    }

    for(int i=0;i<n;i++)adj[i]={};

    for(int i=0;i<u.size();i++)
        adj[u[i]].push_back(v[i]);

    vector<int> outp={};

    for(int i=0;i<n;i++)
    {
        memset(been,0,sizeof(been));
        outp.push_back(1-test(i));
    }
    /*
    for(int i=0;i<n;i++)
    {
        cout<<outp[i]<<" "<<rec(i)<<endl;
    }

    for(int i=0;i<n;i++)
        assert(rec(i)==outp[i]);
    */

    return outp;
}

Compilation message (stderr)

train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:123:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  123 |     for(int i=0;i<a.size();i++)owner[i]=a[i];
      |                 ~^~~~~~~~~
train.cpp:125:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  125 |     for(int i=0;i<r.size();i++)charge[i]=r[i];
      |                 ~^~~~~~~~~
train.cpp:127:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  127 |     for(int i=0;i<u.size();i++)
      |                 ~^~~~~~~~~
train.cpp:165:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  165 |     for(int i=0;i<u.size();i++)
      |                 ~^~~~~~~~~

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 11
• Subtask 4: 11 / 11
• Subtask 5: 0 / 12
• Subtask 6: 0 / 51