Cod sursa(job #2737367)

Utilizator AndreiD31Dragan Andrei AndreiD31 Data 4 aprilie 2021 18:22:26
Problema Flux maxim de cost minim Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.72 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,max_flow,viz[1010],tata[1010],flux[1010][1010],C[1010][1010];

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

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

    for(i=0;i<v[n].size();i++)
    {
        int nod=v[n][i];

        if(viz[nod]==1 && flux[nod][n]<C[nod][n])
        {
            int flux_min=C[nod][n]-flux[nod][n];
            while(tata[nod]!=0)
            {
                flux_min=min(flux_min,C[tata[nod]][nod]-flux[tata[nod]][nod]);
                nod=tata[nod];
            }

            max_flow+=flux_min;

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

    return 1;
}

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

    while(maxflow());
    g<<max_flow;
    return 0;
}