Cod sursa(job #2738779)

Utilizator AndreiD31Dragan Andrei AndreiD31 Data 6 aprilie 2021 12:32:01
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.61 kb
#include <bits/stdc++.h>

using namespace std;

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

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

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

    viz[1]=1;q.push(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(flux[nod][vecin]<C[nod][vecin] && viz[vecin]==0)
            {
                viz[vecin]=1;
                if(vecin!=n)q.push(vecin),tata[vecin]=nod;
            }
        }
    }

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

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

            max_flow+=min_flow;

            nod=v[n][i];
            flux[nod][n]+=min_flow;
            flux[n][nod]-=min_flow;

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

    return 1;
}
int m,x,y,i,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(flux_maxim());

    g<<max_flow;
    return 0;
}