Submission #850551

#	Time	Username	Problem	Language	Result	Execution time	Memory
850551		oscar1f	Monochrome Points (JOI20_monochrome)	C++17	35 / 100	2047 ms	15580 KiB

monochrome

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

#define int long long

const int MAX_VAL=200*1000+5;
int nbVal;
vector<int> initType;
string valDeb;
int cumu[MAX_VAL];

int compt(vector<int> listeBla,vector<int> listeNoir) {
    int nbInter=0,temp,mini,maxi;
    for (int i=0;i<nbVal;i++) {
        mini=min(listeBla[i],listeNoir[i]);
        maxi=max(listeBla[i],listeNoir[i]);
        temp=min(maxi-mini-1,2*nbVal-maxi-1+mini);
        //cout<<listeBla[i]<<" "<<listeNoir[i]<<" "<<temp<<" ";
        nbInter+=temp;
    }
    return nbInter/2;
}

int calc(vector<int> typeSom) {
    int rep=0;
    vector<int> listeBla,listeNoir;
    for (int i=0;i<2*nbVal;i++) {
        if (typeSom[i]==0) {
            listeBla.push_back(i);
        }
        else {
            listeNoir.push_back(i);
        }
    }
    for (int j=0;j<nbVal;j++) {
        cumu[j]=-nbVal;
    }
    int autre,deb,fin,mid,premSup;
    for (int i=0;i<nbVal;i++) {
        //cout<<i<<endl;
        deb=0;
        fin=nbVal;
        while (deb!=fin) {
            mid=(deb+fin)/2;
            if (listeNoir[mid]<listeBla[i]) {
                deb=mid+1;
            } 
            else {
                fin=mid;
            }
        }
        premSup=deb;
        if (premSup>0) {
            deb=0;
            fin=premSup;
            while (deb!=fin) {
                mid=(deb+fin)/2;
                if (listeBla[i]-listeNoir[mid]<nbVal) {
                    fin=mid;
                }
                else {
                    deb=mid+1;
                }
            }
            for (int j=0;j<deb;j++) {
                cumu[(j-i+nbVal)%nbVal]+=2*nbVal-listeBla[i];
                //cout<<"D"<<j<<" ";
            }
            for (int j=deb;j<premSup;j++) {
                cumu[(j-i+nbVal)%nbVal]+=listeBla[i];
                //cout<<"C"<<j<<" ";
            }
            //cout<<deb<<" ";
        }
        //cout<<premSup<<" ";
        if (premSup<nbVal) {
            deb=premSup;
            fin=nbVal;
            while (deb!=fin) {
                mid=(deb+fin)/2;
                if (listeNoir[mid]-listeBla[i]>=nbVal) {
                    fin=mid;
                }
                else {
                    deb=mid+1;
                }
            }
            //cout<<deb<<" ";
            for (int j=premSup;j<deb;j++) {
                cumu[(j-i+nbVal)%nbVal]-=listeBla[i];
                //cout<<"A"<<j<<" ";
            }
            for (int j=deb;j<nbVal;j++) {
                cumu[(j-i+nbVal)%nbVal]+=listeBla[i];
                //cout<<"B"<<j<<" ";
            }
        }
        /*cout<<endl;
        for (int j=0;j<nbVal;j++) {
            autre=listeNoir[j];
            if (listeBla[i]<autre) {
                if (autre-listeBla[i]<nbVal) {
                    //cumu[(j-i+nbVal)%nbVal]-=listeBla[i];
                    cout<<"A"<<j<<" ";
                }
                else {
                    //cumu[(j-i+nbVal)%nbVal]+=listeBla[i];
                    cout<<"B"<<j<<" ";
                }
            }
            else {
                if (listeBla[i]-autre<nbVal) {
                    //cumu[(j-i+nbVal)%nbVal]+=listeBla[i];
                    cout<<"C"<<j<<" ";
                }
                else {
                    //cumu[(j-i+nbVal)%nbVal]+=2*nbVal-listeBla[i];
                    cout<<"D"<<j<<" ";
                }
            }
        }
        cout<<endl;
        cout<<endl;*/
    }
    for (int i=0;i<nbVal;i++) {
        for (int j=0;j<nbVal;j++) {
            autre=listeBla[(i-j+nbVal)%nbVal];
            if (listeNoir[i]<autre) {
                if (autre-listeNoir[i]<nbVal) {
                    cumu[j]-=listeNoir[i];
                }
                else {
                    cumu[j]+=listeNoir[i];
                }
            }
            else {
                if (listeNoir[i]-autre<nbVal) {
                    cumu[j]+=listeNoir[i];
                }
                else {
                    cumu[j]+=2*nbVal-listeNoir[i];
                }
            }
        }
    }
    for (int j=0;j<nbVal;j++) {
        rep=max(rep,cumu[j]/2);
    }
    return rep;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin>>nbVal;
    cin>>valDeb;
    for (int i=0;i<2*nbVal;i++) {
        if (valDeb[i]=='W') {
            initType.push_back(0);
        }
        else {
            initType.push_back(1);
        }
    }
    cout<<calc(initType)<<endl;
    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 21 / 21
• Subtask 3: 10 / 10
• Subtask 4: 0 / 65