Submission #1079427

#	Time	Username	Problem	Language	Result	Execution time	Memory
1079427		oscar1f	Tiles (BOI24_tiles)	C++17	100 / 100	97 ms	17600 KiB

Main

#include<bits/stdc++.h>
using namespace std;
 
#define int long long
 
struct sommet {
    int x,y,ordreParc;
    bool operator < (const sommet& autre) const {
        if (x!=autre.x) {
            return (x<autre.x);
        }
        return (y<autre.y);
    }
};



const int INFINI=1000*1000*1000+6,TAILLE_MAX=200*1000+5,COORD_MAX=1000+5;
int nbPoints,maxX,nbImpair;
pair<int,int> initPoint[TAILLE_MAX];
pair<int,int> points[TAILLE_MAX];
int cumu[COORD_MAX][COORD_MAX];
int emboite[TAILLE_MAX];
set<pair<int,int>> enCours[2];

void fusion(int deb,int fin,int pari) {
    enCours[pari].insert({deb,fin});
    nbImpair+=(fin-deb)%2;
    auto it=enCours[pari].lower_bound({fin,-INFINI});
    int nouvDeb,nouvFin;
    if ((*it).first==fin) {
        nbImpair-=((*it).second-(*it).first)%2;
        nbImpair-=(fin-deb)%2;
        nouvFin=(*it).second;
        enCours[pari].erase(it);
        it=enCours[pari].lower_bound({deb,fin});
        enCours[pari].erase(it);
        fin=nouvFin;
        enCours[pari].insert({deb,fin});
        nbImpair+=(fin-deb)%2;
    }
    it=enCours[pari].lower_bound({deb,fin});
    it--;
    if ((*it).second==deb) {
        nbImpair-=((*it).second-(*it).first)%2;
        nbImpair-=(fin-deb)%2;
        nouvDeb=(*it).first;
        enCours[pari].erase(it);
        it=enCours[pari].lower_bound({deb,fin});
        enCours[pari].erase(it);
        deb=nouvDeb;
        enCours[pari].insert({deb,fin});
        nbImpair+=(fin-deb)%2;
    }
}
 
void suppr(int deb,int fin,int pari) {
    auto it=enCours[pari].lower_bound({deb,fin});
    if ((*it).first==deb) {
        if ((*it).second==fin) {
            nbImpair-=(fin-deb)%2;
            enCours[pari].erase(it);
        }
        else {
            nbImpair-=((*it).second-deb)%2;
            deb=fin;
            fin=(*it).second;
            enCours[pari].erase(it);
            nbImpair+=(fin-deb)%2;
            enCours[pari].insert({deb,fin});
        }
    }
    else {
        it--;
        if ((*it).second==fin) {
            nbImpair-=(fin-(*it).first)%2;
            fin=deb;
            deb=(*it).first;
            enCours[pari].erase(it);
            nbImpair+=(fin-deb)%2;
            enCours[pari].insert({deb,fin});
        }
        else {
            int premDeb=(*it).first,dernFin=(*it).second;
            nbImpair-=(dernFin-premDeb)%2;
            enCours[pari].erase(it);
            enCours[pari].insert({premDeb,deb});
            enCours[pari].insert({fin,dernFin});
            nbImpair+=(deb-premDeb)%2;
            nbImpair+=(dernFin-fin)%2;
        }
    }
}
 
bool intersecte(int deb,int fin,int pari) {
    auto it=enCours[pari].lower_bound({fin,-INFINI});
    it--;
    return (*it).second>deb;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin>>nbPoints>>maxX;
    int xNouv,yNouv,posMin=0,xMin=INFINI,yMin=INFINI,maxY=0,somX=0;
    for (int i=0;i<nbPoints;i++) {
        cin>>xNouv>>yNouv;
        if (xNouv<xMin or (xNouv==xMin and yNouv<yMin)) {
            posMin=i;
            xMin=xNouv;
            yMin=yNouv;
        }
        maxY=max(maxY,yNouv);
        somX+=xNouv%2;
        initPoint[i]={xNouv,yNouv};
    }
    int posCour,direc=-1,nbPris=1;
    points[0]={xMin,yMin};
    for (int i=1;i<=nbPoints;i++) {
        posCour=(posMin+i)%nbPoints;
        if (points[nbPris-1].first==initPoint[posCour].first) {
            if (direc==0) {
                points[nbPris-1].second=initPoint[posCour].second;
            }
            else {
                direc=0;
                points[nbPris]=initPoint[posCour];
                nbPris++;
            }
        }
        else {
            if (direc==1) {
                points[nbPris-1].first=initPoint[posCour].first;
            }
            else {
                direc=1;
                points[nbPris]=initPoint[posCour];
                nbPris++;
            }
        }
    }
    nbPoints=nbPris;
    if (direc==0) {
        for (int i=0;i<nbPoints/2;i++) {
            swap(points[i],points[nbPoints-1-i]);
        }
    }

    int rep=0;
    vector<sommet> somTri;
    for (int i=0;i<nbPoints-1;i++) {
        somTri.push_back({points[i].first,points[i].second,i});
    }
    somTri.push_back({INFINI,INFINI,nbPoints});
    sort(somTri.begin(),somTri.end());
    for (int i=0;i<2;i++) {
        enCours[i].insert({-INFINI,-42});
        enCours[i].insert({INFINI,42});
    }
    for (int i=0;i<nbPoints-1;i+=2) {
        if ((int)enCours[0].size()==2 and (i==0 or somTri[i].x!=somTri[i-2].x)) {
            if (somTri[i].x%2==0) {
                rep=max(rep,somTri[i].x-1);
            }
            else {
                rep=max(rep,somTri[i].x);
            }
        }
        if ((int)enCours[1].size()==2 and (i==0 or somTri[i].x!=somTri[i-2].x)) {
            if (somTri[i].x%2==0) {
                rep=max(rep,somTri[i].x);
            }
            else {
                rep=max(rep,somTri[i].x-1);
            }
        }
        if (somTri[i].ordreParc<somTri[i+1].ordreParc) {
            fusion(somTri[i].y,somTri[i+1].y,somTri[i].x%2);
        }
        else {
            if (intersecte(somTri[i].y,somTri[i+1].y,1-somTri[i].x%2)) {
                cout<<rep<<endl;
                return 0;
            }
            suppr(somTri[i].y,somTri[i+1].y,somTri[i].x%2);
        }
        if (somTri[i].x!=somTri[i+2].x and nbImpair>0) {
            cout<<rep<<endl;
            return 0;
        } 
    }
    cout<<maxX<<endl;
    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 9 / 9
• Subtask 3: 11 / 11
• Subtask 4: 19 / 19
• Subtask 5: 22 / 22
• Subtask 6: 25 / 25
• Subtask 7: 10 / 10