Cod sursa(job #2330419)

Utilizator ionanghelinaIonut Anghelina ionanghelina Data 28 ianuarie 2019 12:54:31
Problema Traseu Scor 20
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 3.07 kb
#include<bits/stdc++.h>
using namespace std;

int n;
const int maxN=65;
priority_queue<pair<int,int> > q;
vector<int> v[maxN];
int c[maxN][maxN],cst[maxN][maxN],pred[maxN],fat[maxN];
const int inf=(1e9);
int dist[maxN],rd[maxN];
int sol;

struct tip
{
    int cost,nod;
    bool operator<(const tip&other) const
    {
        return make_pair(cost,nod)>make_pair(other.cost,other.nod);
    }
};

set<tip> Set;
bool inSet[maxN];

inline bool dijkstra()
{
    for(int i=0;i<=n+1;i++) dist[i]=inf;
    dist[0]=0;
    rd[0]=0;

    Set.insert({0,0});


    while(!Set.empty())
    {
        set<tip>::iterator it=Set.begin();

        int nod=(*it).nod;

        Set.erase(Set.begin());


        for(auto it:v[nod])
        {
            if(!c[nod][it]) continue;
            if(dist[it]>dist[nod]+cst[nod][it]+pred[nod]-pred[it]);
            {
                tip nr;
                nr.cost=-dist[it];
                nr.nod=it;

                if(inSet[it]) Set.erase(Set.find(nr));

                dist[it]=dist[nod]+cst[nod][it]+pred[nod]-pred[it];
                rd[it]=rd[nod]+cst[nod][it];

                nr.cost=-dist[it];
                nr.nod=it;

                Set.insert({nr});
                inSet[it]=1;
               // q.push({-dist[it],it});
                fat[it]=nod;
            }
        }
    }

    for(int i=0;i<=n+1;i++)
        pred[i]=rd[i];

    if(dist[n+1]==inf) return 0;


    int f=2e9,ans=0;
    for(int T=n+1;T!=0;T=fat[T])
    {
        f=min(f,c[fat[T]][T]);
        ans=ans+cst[fat[T]][T];
    }

    sol=sol+f*rd[n+1];

    for(int T=n+1;T!=0;T=fat[T])
    {
        c[fat[T]][T]-=f;
        c[T][fat[T]]+=f;
    }

    return 1;
}
int m,in[maxN],out[maxN];

int main()
{
    freopen("traseu.in","r",stdin);
    freopen("traseu.out","w",stdout);


    scanf("%d%d",&n,&m);

    for(int i=1;i<=n;i++)
        for(int j=1;j<=n;j++)
            if(i!=j) cst[i][j]=inf;


    for(int i=1;i<=m;i++)
    {
        int x,y,z;
        scanf("%d%d%d",&x,&y,&z);
        cst[x][y]=z;
        sol=sol+z;
        in[y]++;
        out[x]++;
    }

    for(int k=1;k<=n;k++)
    {
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++)
                if(cst[i][k] && cst[k][j]) cst[i][j]=min(cst[i][j],cst[i][k]+cst[k][j]);
    }



    for(int i=1;i<=n;i++)
    {
        if(in[i]>out[i])
        {
            v[0].push_back(i);
            v[i].push_back(0);
            c[0][i]=in[i]-out[i];

        }
            else
        {
            v[i].push_back(n+1);
            v[n+1].push_back(i);
            c[i][n+1]=out[i]-in[i];
        }
    }

    for(int i=1;i<=n;i++)
    {
        if(in[i]>out[i])
        {
            for(int j=1;j<=n;j++)
                if(in[j]<out[j])
            {
                v[i].push_back(j);
                v[j].push_back(i);
                c[i][j]=inf;
                cst[j][i]=-cst[i][j];
            }
        }
    }

    while(dijkstra());

    printf("%d\n",sol);
    return 0;
}