Cod sursa(job #2574203)

Utilizator spartanul300Vasile Andrei spartanul300 Data 5 martie 2020 20:55:37
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.75 kb
#include <bits/stdc++.h>

using namespace std;

ifstream f("maxflow.in");
ofstream g("maxflow.out");

vector <int> v[1010];
queue <int> q;
int n,maxflow,C[1010][1010],flux[1010][1010],tata[1010],viz[1010];

int flux_maxim()
{
    int i,nod,vecin,flux_min=INT_MAX;

    for(i=1;i<=n;i++)viz[i]=0,tata[i]=0;

    q.push(1);
    viz[1]=1;

    while(!q.empty())
    {
        nod=q.front();
        q.pop();
        for(i=0;i<v[nod].size();i++)
        {
            int vecin=v[nod][i];
            if(flux[nod][vecin]<C[nod][vecin] && viz[vecin]==0)
            {
                viz[vecin]=1;
                tata[vecin]=nod;
                q.push(vecin);
            }
        }
    }

    if(viz[n]==0)return 0;

    for(i=0;i<v[n].size();i++)
    {
        vecin=v[n][i];
        if(viz[vecin]==1 && flux[vecin][n]<C[vecin][n])
        {
            int flux_min=C[vecin][n]-flux[vecin][n];
            nod=vecin;
            while(tata[nod]!=0)
            {
                flux_min=min(flux_min,C[tata[nod]][nod]-flux[tata[nod]][nod]);
                nod=tata[nod];
            }

            maxflow+=flux_min;

            flux[vecin][n]+=flux_min;
            flux[n][vecin]-=flux_min;
            nod=vecin;
            while(tata[nod]!=0)
            {
                flux[tata[nod]][nod]+=flux_min;
                flux[nod][tata[nod]]-=flux_min;
                nod=tata[nod];
            }
        }
    }

    return 1;
}

int m,i,mch_capacitate,x,y;
int main()
{
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>x>>y>>mch_capacitate;
        v[x].push_back(y);
        v[y].push_back(x);
        C[x][y]=mch_capacitate;
    }

    while(flux_maxim());
    g<<maxflow;

    return 0;
}