Cod sursa(job #357419)

Utilizator DraStiKDragos Oprica DraStiK Data 19 octombrie 2009 11:27:27
Problema Critice Scor 70
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.89 kb
#include <stdio.h>

#define DIM 1005
#define oo 1<<30-1

struct nod {int x;
            nod *urm;} *lst[DIM];
int c[DIM][DIM],f[DIM][DIM];
int q[DIM],t[DIM],sol[10*DIM];
int n,m,nrt;

void add (int a,int b)
{
    nod *p=new nod;
    p->x=a;
    p->urm=lst[b];
    lst[b]=p;
}

void read ()
{
	freopen ("critice.in","r",stdin);
	int i,x,y,z;

	scanf ("%d%d",&n,&m);
	for (i=1; i<=m; ++i)
	{
		scanf ("%d%d%d",&x,&y,&z);
		c[x][y]=c[y][x]=z;
		add (x,y);
		add (y,x);
	}
}

int bf ()
{
    int st,dr,i;
    nod *p;

    for (i=1; i<=n; ++i)
        t[i]=0;
    for (q[st=dr=1]=1; st<=dr; ++st)
        for (p=lst[q[st]]; p; p=p->urm)
            if (!t[p->x] && c[q[st]][p->x]>f[q[st]][p->x])
            {
                t[p->x]=q[st];
                q[++dr]=p->x;
            }
    return t[n];
}

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

void flux ()
{
    int i,j,minim,flow;

    for ( ; bf (); )
		for (i=1; i<=n; ++i)
		    if (t[i]>0 && c[i][n]-f[i][n]>0)
		    {
				minim=c[i][n]-f[i][n];
    			for (j=i; j!=1; j=t[j])
    				minim=min (minim,c[t[j]][j]-f[t[j]][j]);
                f[i][n]+=minim;
                f[n][i]-=minim;
    			for (j=i; j!=1; j=t[j])
                {
                    f[t[j]][j]+=minim;
                    f[j][t[j]]-=minim;
                }
        	}
}

void solve ()
{
    freopen ("critice.in","r",stdin);
    freopen ("critice.out","w",stdout);
    int i,x,y,z;

    flux ();
    scanf ("%d%d",&n,&m);
	for (i=1; i<=m; ++i)
	{
		scanf ("%d%d%d",&x,&y,&z);
		c[x][y]=c[y][x]=z+1;
		if (bf ())
            sol[++nrt]=i;
        c[x][y]=c[y][x]=z;
	}
}

void print ()
{
    int i;

    printf ("%d\n",nrt);
    for (i=1; i<=nrt; ++i)
        printf ("%d\n",sol[i]);
}

int main ()
{
    read ();
    solve ();
    print ();

    return 0;
}