Submission #1092359

#	Time	Username	Problem	Language	Result	Execution time	Memory
1092359		TlenekWodoru	Fountain Parks (IOI21_parks)	C++17	100 / 100	1713 ms	125832 KiB

parks

#include<bits/stdc++.h>
#include "parks.h"
using namespace std;
struct Edge
{
    int som,ind;
};
map<pair<int,int>,int>M,M2;
vector<Edge>Graf[200009];
vector<int>D[1000009];
pair<int,int>KimJest[1000009];
bool zaj[1000009];
vector<int>Sprz;
int g[1000009];
int match[1000009];
int n,m=0,k=0,N,IleVert=0;
int f[200009],ilosc[200009];
bool Zaj[1000009];
int F(int v)
{
    if(f[v]==v){return v;}
    return f[v]=F(f[v]);
}
void Polacz(int a, int b)
{
    a=F(a);
    b=F(b);
    if(a==b){return;}
    if(ilosc[a]<ilosc[b]){swap(a,b);}
    ilosc[a]+=ilosc[b];
    f[b]=a;
}
bool DFS(int v)
{
    if(zaj[v]){return 0;}
    zaj[v]=1;
    Sprz.push_back(v);
    for(int som : D[v])
    {
        if(match[som]==-1||DFS(match[som]))
        {
            match[v]=som;
            match[som]=v;
            return 1;
        }
    }
    return 0;
}
void BFS()
{
    int start=0;
    Zaj[start]=1;
    deque<int>Y;
    Y.push_back(start);
    while((int)Y.size()>0)
    {
        const int v=Y[0];
        Y.pop_front();
        for(int som : D[v])
        {
            if(Zaj[som]==0)
            {
                Zaj[som]=1;
                Y.push_back(som);
                if(match[v]==-1&&match[som]==-1)
                {
                    match[v]=som;
                    match[som]=v;
                }
            }
        }
    }
}
void SKOJ()
{
    random_shuffle(g,g+N);
    for(int i=0;i<N;i++)
    {
        match[i]=-1;
        zaj[i]=0;
        random_shuffle(D[i].begin(),D[i].end());
    }
    BFS();
    random_shuffle(g,g+N);
    return;
    for(int i=0;i<N;i++)
    {
        int u=g[i];
        if(match[u]==-1)
        {
            DFS(u);
        }
        for(int temp : Sprz)
        {
            zaj[temp]=0;
        }
        Sprz.clear();
    }
}
void Upgrade(int v)
{
    zaj[v]=1;
    Sprz.push_back(v);
    for(int som : D[v])
    {
        if(zaj[match[som]]==0)
        {
            Upgrade(match[som]);
            match[v]=som;
            match[som]=v;
            return;
        }
        else if(match[som]!=v)
        {
            break;
        }
    }
    for(int u : Sprz){zaj[u]=0;}
    Sprz.clear();
    match[v]=-1;
}
void CzySpojna(int v)
{
    zaj[v]=1;
    IleVert++;
    for(auto[som,ind] : Graf[v])
    {
        if(zaj[som]){continue;}
        CzySpojna(som);
    }
}
int construct_roads(vector<int>X, vector<int>Y)
{
    srand(2137);
    n=(int)X.size();
    for(int i=0;i<n;i++)
    {
        M[{X[i],Y[i]}]=i;
    }
    for(int i=0;i<n;i++)
    {
        if(M.find({X[i]-2,Y[i]})!=M.end())
        {
            Graf[i].push_back({M[{X[i]-2,Y[i]}],m});
            Graf[M[{X[i]-2,Y[i]}]].push_back({i,m});
            m++;
        }
        if(M.find({X[i],Y[i]-2})!=M.end())
        {
            Graf[i].push_back({M[{X[i],Y[i]-2}],m});
            Graf[M[{X[i],Y[i]-2}]].push_back({i,m});
            m++;
        }
    }
    CzySpojna(0);
    if(IleVert!=n){return 0;}
    vector<pair<int,int>>E(m);
    for(int i=0;i<n;i++)
    {
        for(auto[som,ind] : Graf[i])
        {
            int a=i,b=som;
            if(pair<int,int>{X[a],Y[a]}>pair<int,int>{X[b],Y[b]}){continue;}
            E[ind]={a,b};
        }
    }
    for(int i=0;i<(int)E.size();i++)
    {
        const int a=E[i].first,b=E[i].second;
        vector<pair<int,int>>Som;
        if(Y[a]+2==Y[b])
        {
            Som.push_back({X[a]-1,Y[a]+1});
            Som.push_back({X[a]+1,Y[a]+1});
        }
        else if(X[a]+2==X[b])
        {
            Som.push_back({X[a]+1,Y[a]+1});
            Som.push_back({X[a]+1,Y[a]-1});
        }
        for(pair<int,int>som : Som)
        {
            if(M2.find(som)==M2.end())
            {
                KimJest[k]=som;
                M2[som]=k++;
            }
            int u=m+M2[som];
            D[i].push_back(u);
            D[u].push_back(i);
        }
    }
    N=m+k;
    for(int i=0;i<N;i++){g[i]=i;}
    SKOJ();
for(int I=1;I<=100;I++)
{
    for(int i=0;i<n;i++)
    {
        f[i]=i;
        ilosc[i]=1;
    }
    for(int i=0;i<n;i++)
    {
        for(auto[som,ind] : Graf[i])
        {
            if(match[ind]==-1){continue;}
            Polacz(i,som);
        }
    }
    if(ilosc[F(0)]==n)
    {
        vector<int>O1,O2,O3,O4;
        for(int j=0;j<m;j++)
        {
            const int a=E[j].first,b=E[j].second;
            if(match[j]!=-1)
            {
                pair<int,int>xd=KimJest[match[j]-m];
                O1.push_back(a);
                O2.push_back(b);
                O3.push_back(xd.first);
                O4.push_back(xd.second);
            }
        }
        build(O1,O2,O3,O4);
        return 1;
    }
    vector<int>U;
    for(int i=0;i<n;i++){g[i]=i;}
    random_shuffle(g,g+n);
    for(int i=0;i<n;i++)
    {
        const int u=g[i];
        for(auto[som,ind] : Graf[u])
        {
            if(match[ind]==-1&&F(u)!=F(som))
            {
                U.push_back(ind);
                Polacz(u,som);
            }
        }
    }
    for(int u : U)
    {
        if(match[u]!=-1){continue;}
        Upgrade(u);
    }
}
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20
• Subtask 6: 30 / 30