Cod sursa(job #928169)

Utilizator misinozzz zzz misino Data 26 martie 2013 12:04:02
Problema Flux maxim Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.21 kb
#include<fstream>
#include<cstring>
using namespace std;
ifstream f("maxflow.in");
ofstream g("maxflow.out");
int mini,i,s,d,x,y,z,n,flux,m,t[1010],q[1010],grin[1010],grext[1010],c[1010][1010],fl[1010][1010];
int bfs()
{
    int i,x,p=1,u=1;
    q[1]=s;
    memset(t,0,sizeof(t));
    t[s]=-1;
    while(p<=u)
    {
        x=q[p];
        ++p;
        for(i=1;i<=n;++i)
        if(!t[i]&&c[x][i]>fl[x][i])
        {
            ++u;
            q[u]=i;
            t[i]=x;
            if(i==d)
            return 1;
        }
    }
    return 0;
}
int main()
{
    f>>n>>m;
    for(i=1;i<=m;++i)
    {
        f>>x>>y>>z;
        c[x][y]=z;
        grin[y]++;
        grext[x]++;
    }
    for(i=1;i<=n;++i)
    if(grin[i]==0)
    {
        s=i;
    }
    else
    if(grext[i]==0)
    {
        d=i;
    }
    while(bfs())
    {
        i=d;
        mini=999999999;
        while(i!=s)
        {
            mini=min(mini,c[t[i]][i]-fl[t[i]][i]);
            i=t[i];
        }
        i=d;
        while(i!=s)
        {
            fl[t[i]][i]+=mini;
            fl[i][t[i]]-=mini;
            i=t[i];
        }
        flux+=mini;
    }
    g<<flux<<'\n';
    return 0;
}