Cod sursa(job #360077)

Utilizator DraStiKDragos Oprica DraStiK Data 29 octombrie 2009 15:40:20
Problema Cc Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.9 kb
#include <stdio.h>

#define DIM 205
#define oo 1<<31-1

struct nod {int x;
            nod *urm;} *lst[DIM];
int c[DIM][DIM],f[DIM][DIM],ct[DIM][DIM];
int q[10*DIM*DIM],viz[DIM],t[DIM],dist[DIM];
int n,m,s,d,minim;
long long cost;

void add (int x,int y)
{
    nod *p=new nod;

    p->x=x;
    p->urm=lst[y];
    lst[y]=p;
}

void read ()
{
    int i,j;

    scanf ("%d",&n);
    s=0; d=2*n+1;
    for (i=1; i<=n; ++i)
        for (j=1; j<=n; ++j)
        {
            scanf ("%d",&ct[i][j+n]);
            ct[j+n][i]=-ct[i][j+n];
            add (i,j+n); add (j+n,i);
            add (s,i); add (i,s);
            add (j+n,d); add (d,j+n);
            c[i][j+n]=c[s][i]=c[j+n][d]=1;
        }
}

int bellman_ford ()
{
    int st,dr;
    nod *p;

    for (dist[q[st=dr=1]=s]=0; st<=dr; viz[q[st++]]=0)
        for (p=lst[q[st]]; p; p=p->urm)
            if (c[q[st]][p->x]>f[q[st]][p->x] && dist[q[st]]+ct[q[st]][p->x]<dist[p->x])
            {
                dist[p->x]=dist[q[st]]+ct[q[st]][p->x];
                t[p->x]=q[st];
                if (!viz[p->x])
                    viz[q[++dr]=p->x]=1;
            }
    if (dist[d]!=oo)
        return 1;
    return 0;
}

void init ()
{
    int i;

    for (i=s; i<=d; ++i)
    {
        t[i]=viz[i]=0;
        dist[i]=oo;
    }
    minim=oo;
}

int min (int a,int b)
{
    if (a<b)
        return a;
    return b;
}

void solve ()
{
    int i;

    for (init (); bellman_ford (); init ())
    {
        for (i=d; i!=s; i=t[i])
            minim=min (minim,c[t[i]][i]-f[t[i]][i]);
        for (i=d; i!=s; i=t[i])
        {
            f[t[i]][i]+=minim;
            f[i][t[i]]-=minim;
        }
        cost+=minim*dist[d];
    }
    printf ("%lld",cost);
}

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

    read ();
    solve ();

    return 0;
}