Cod sursa(job #2545810)

Utilizator iulianarsenoiuArsenoiu Iulian iulianarsenoiu Data 13 februarie 2020 15:46:11
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.63 kb
#include <bits/stdc++.h>

using namespace std;
ifstream f("maxflow.in");
ofstream g("maxflow.out");
int t[1005],c[1005][1005],F[1005][1005],n,m;
vector <int> G[1005];
bool bfs(int s, int d)
{
    for(int i=1;i<=n;i++)
        t[i]=-1;
    t[s]=0;
    queue <int> q;
    q.push(s);
    while(!q.empty())
    {
        int x=q.front();
        q.pop();
        for(auto it : G[x])
        {
            if(t[it]==-1 && c[x][it]>F[x][it])
            {
                q.push(it);
                t[it]=x;
                if(it==d)
                {
                    return true;
                }
            }
        }
    }
    return false;
}
int MaxFlow(int s, int d)
{
    int flux=0;
    while(bfs(s,d))
    {
        for(auto it : G[d])
        if(t[it]!=-1)
        {
            int Add=c[it][d]-F[it][d];
            int nod=it;
            int dad=t[it];
            while(nod!=s)
            {
                Add=min(Add,c[dad][nod]-F[dad][nod]);
                nod=dad;
                dad=t[nod];
            }
            flux+=Add;
            F[it][d]+=Add;
            F[d][it]-=Add;
            nod=it;
            dad=t[it];
            while(nod!=s)
            {
                F[nod][dad]-=Add;
                F[dad][nod]+=Add;
                nod=dad;
                dad=t[nod];
            }
        }
    }
    return flux;
}
int main()
{
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int x,y,cap;
        f>>x>>y>>cap;
        c[x][y]=cap;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    g<<MaxFlow(1,n)<<'\n';
    return 0;
}