Cod sursa(job #2129293)

Utilizator RaduXD1Nicolae Radu RaduXD1 Data 12 februarie 2018 18:22:50
Problema Flux maxim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.59 kb
#include <fstream>
#include <vector>
#define DIM 1001
using namespace std;
ifstream fin("maxflow.in");
ofstream fout("maxflow.out");
int n,m,i,mini,ve,a,b,cap, sol;
int c[DIM][DIM], f[DIM][DIM];
int d[DIM], z[DIM], t[DIM];
vector<int> v[DIM];


int bfs()
{
    int p=1, u=1, i, nod,vecin;
    for(i=1;i<=n;i++)
        d[i]=0;
    z[1]=1;
    d[1]=1;
    while(p<=u)
    {
        nod=z[p];
        for(i=0;i<v[nod].size();i++)
        {
            vecin=v[nod][i];
            if(c[nod][vecin]>f[nod][vecin]&&d[vecin]==0)
            {
                u++;
                z[u]=vecin;
                d[vecin]=1;
                t[vecin]=nod;
            }
        }
        p++;
    }
    return d[n];
}

int main()
{
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>a>>b>>cap;
        v[a].push_back(b);
        v[b].push_back(a);
        c[a][b]=cap;
    }
    while(bfs()==1)
    {
        for(i=0;i<v[n].size();i++)
        {
            ve=v[n][i];
            if(d[ve]==1&&c[ve][n]>f[ve][n])
            {
                a=ve;b=n;
                mini=c[ve][n]-f[ve][n];
                while(a!=0)
                {
                    mini=min(mini, c[a][b]-f[a][b]);
                    b=a;a=t[a];
                }
                a=ve;b=n;
                while(a!=0)
                {
                    f[a][b]+=mini;
                    f[b][a]-=mini;
                    b=a;a=t[a];
                }
                f[n][ve]+=mini;
                sol+=mini;
            }
        }
    }
    fout<<sol;
    return 0;
}