Cod sursa(job #2690266)

Utilizator armigheGheorghe Liviu Armand armighe Data 23 decembrie 2020 14:55:13
Problema Adapost Scor 100
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 5.22 kb
#include<bits/stdc++.h>
#define INF 2000000000
using namespace std;
ifstream f("adapost.in");
ofstream g("adapost.out");
vector<int>a[402];
int n,st[402],dr[402],sol_cuplaj;
bool tried[402];
long double Zs[160002];
pair<long double,long double>v[802];
struct nod
{
    int x,poz;
};
vector<nod>A[805];
nod tata[805];
int s,d,flux,r[322002],poz;
long double dist[805],dist2[805],realdist[805];
long double z[322002],sol_flux;
bool inq[805];
queue<int>q;
struct elem
{
    int x;
    long double dist;
    inline bool operator < (const elem &a) const
    {
        return dist>a.dist;
    }
};
priority_queue<elem>pq;

bool cupleaza(int x)
{
    if(tried[x]==1)
        return 0;
    tried[x]=1;
    for(auto y:a[x])
    if(dr[y]==0)
    {
        sol_cuplaj++;
        st[x]=y;
        dr[y]=x;
        return 1;
    }
    for(auto y:a[x])
    if(cupleaza(dr[y])==1)
    {
        st[x]=y;
        dr[y]=x;
        return 1;
    }
    return 0;
}

void cuplaj()
{
    int i;
    bool ok=1;
    while(ok==1)
    {
        for(i=1;i<=n;i++)
            tried[i]=0;
        ok=0;
        for(i=1;i<=n;i++)
        if(st[i]==0)
            ok|=cupleaza(i);
    }
}

long double calc_dist(int x,int y)
{
    long double sol;
    sol=(v[x].first-v[y].first)*(v[x].first-v[y].first)+(v[x].second-v[y].second)*(v[x].second-v[y].second);
    sol=sqrtl(sol);
    return sol;
}

inline bool dijkstra()
{
    int i,l;
    long double Z;
    elem p;
    for(i=1;i<=n;i++)
        dist[i]=INF,tata[i]={0,0};
    pq.push({s,0});
    dist[s]=0;
    dist2[s]=0;
    while(!pq.empty())
    {
        p=pq.top();
        pq.pop();
        if(p.dist==dist[p.x])
        {
            l=A[p.x].size();
            for(i=0;i<l;i++)
            {
                Z=realdist[p.x]-realdist[A[p.x][i].x]+z[A[p.x][i].poz];
                if(r[A[p.x][i].poz]>0)
                if(z[A[p.x][i].poz]<=Zs[poz]&&z[A[p.x][i].poz]>=-Zs[poz])
                if(dist[A[p.x][i].x]>dist[p.x]+Z)
                {
                    dist[A[p.x][i].x]=dist[p.x]+Z;
                    dist2[A[p.x][i].x]=dist2[p.x]+z[A[p.x][i].poz];
                    tata[A[p.x][i].x].x=p.x;
                    tata[A[p.x][i].x].poz=A[p.x][i].poz;
                    pq.push({A[p.x][i].x,dist[A[p.x][i].x]});
                }
            }
        }
    }
    for(i=1;i<=n;i++)
        realdist[i]=dist2[i];
    return dist[d]!=INF;
}

inline void bellman_ford()
{
    int i,l,p;
    for(i=1;i<=n;i++)
        realdist[i]=INF,inq[i]=0;
    realdist[s]=0;
    q.push(s);
    inq[s]=1;
    while(!q.empty())
    {
        p=q.front();
        q.pop();
        inq[p]=0;
        l=A[p].size();
        for(i=0;i<l;i++)
        if(r[A[p][i].poz]>0)
        if(z[A[p][i].poz]<=Zs[poz]&&z[A[p][i].poz]>=-Zs[poz])
        if(realdist[A[p][i].x]>realdist[p]+z[A[p][i].poz])
        {
            realdist[A[p][i].x]=realdist[p]+z[A[p][i].poz];
            if(inq[A[p][i].x]==0)
            {
                q.push(A[p][i].x);
                inq[A[p][i].x]=1;
            }
        }
    }
}

inline void fmcm()
{
    int i,flow;
    long double cost;
    bellman_ford();
    while(dijkstra()!=0)
    {
        flow=INF;
        for(i=d;i!=s;i=tata[i].x)
        {
            flow=min(flow,r[tata[i].poz]);
            if(flow==0)
                break;
        }
        if(flow!=0&&flow!=INF)
        {
            cost=0;
            for(i=d;i!=s;i=tata[i].x)
            {
                r[tata[i].poz]-=flow;
                r[tata[i].poz^1]+=flow;
                cost+=z[tata[i].poz];
            }
            flux+=flow;
            sol_flux+=flow*cost;
        }
    }
}

int main()
{
    int i,j,left,right,mij,k=0;
    long double zz;
    f>>n;
    for(i=1;i<=2*n;i++)
        f>>v[i].first>>v[i].second;
        for(i=1;i<=n;i++)
    for(j=1;j<=n;j++)
        Zs[(i-1)*n+j]=calc_dist(i,j+n);
    sort(Zs+1,Zs+n*n+1);
    left=1;
    right=n*n;
    while(left<=right)
    {
        mij=(left+right)/2;
        sol_cuplaj=0;
        for(i=1;i<=n;i++)
            st[i]=dr[i]=tried[i]=0,a[i].clear();
        for(i=1;i<=n;i++)
        for(j=1;j<=n;j++)
        if(calc_dist(i,j+n)<=Zs[mij])
            a[i].push_back(j);
        cuplaj();
        if(sol_cuplaj==n)
        {
            poz=mij;
            right=mij-1;
        }
        else
            left=mij+1;
    }
    for(i=1;i<=n;i++)
    for(j=1;j<=n;j++)
    if(calc_dist(i,j+n)<=Zs[poz])
    {
        zz=calc_dist(i,j+n);
        r[k]=1;
        z[k]=zz;
        A[i].push_back({j+n,k});
        k++;
        r[k]=0;
        z[k]=-zz;
        A[j+n].push_back({i,k});
        k++;
    }
    s=2*n+1;
    d=2*n+2;
    for(i=1;i<=n;i++)
    {
        r[k]=1;
        z[k]=0;
        A[s].push_back({i,k});
        k++;
        r[k]=0;
        z[k]=0;
        A[i].push_back({s,k});
        k++;
        r[k]=1;
        z[k]=0;
        A[i+n].push_back({d,k});
        k++;
        r[k]=0;
        z[k]=0;
        A[d].push_back({i+n,k});
        k++;
    }
    n=n*2+2;
    fmcm();
    g<<fixed<<setprecision(5)<<Zs[poz]<<" "<<fixed<<setprecision(5)<<sol_flux;
    return 0;
}