Cod sursa(job #1120229)

Utilizator Eugen_VlasieFMI Vlasie Eugen Eugen_Vlasie Data 24 februarie 2014 22:19:25
Problema Flux maxim Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.79 kb
#include <fstream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <vector>
#include <queue>
using namespace std;
ifstream f("maxflow.in");
ofstream g("maxflow.out");
vector <long long> a[1005];
queue <long long> q;
long long v[1005][1005],n,m,viz[1005],pred[1005],urm[1005];
long long nod,i,x,y,c,fmax=0,n1,d1;
long long bfs()
{
    memset(viz,0,sizeof(viz));
    memset(pred,0,sizeof(pred));
    q.push(1);
    viz[1]=1;
    while(!q.empty())
    {
        nod=q.front();
        q.pop();
        for(vector<long long>::iterator it=a[nod].begin();it!=a[nod].end();it++)
        {
            n1=(*it);
            if(!viz[n1]&&v[nod][n1])
            {
                viz[n1]++;
                q.push(n1);
                pred[n1]=nod;
                if(n1==n)
                {
                    while(!q.empty())
                        q.pop();
                    break;
                }
            }
        }
    }
    nod=n;
    y=110010;
    while(pred[nod])
    {
        if(v[pred[nod]][nod]< y)
            y=v[pred[nod]][nod];
        nod=pred[nod];
    }
    if(y==110010)
        return 0;
    else
    {
        nod=n;
        while(pred[nod])
        {
            v[pred[nod]][nod]-=y;
            v[nod][pred[nod]]+=y;
            nod=pred[nod];
        }
        return y;
    }
}
int main()
{
    //freopen("maxflow.in","r",stdin);
    //scanf("%d",&n);
    //scanf("%d",&m);
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        //scanf("%d",&x);
        //scanf("%d",&y);
        //scanf("%d",&c);
        f>>x>>y>>c;
        a[x].push_back(y);
        a[y].push_back(x);
        v[x][y]=c;
    }
    x=bfs();
    while(x)
    {
        fmax+=x;
        x=bfs();
    }
    g<<fmax<<'\n';
    return 0;
}