Cod sursa(job #2739404)

Utilizator hhhhhhhAndrei Boaca hhhhhhh Data 8 aprilie 2021 10:10:39
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.62 kb
#include <bits/stdc++.h>

using namespace std;
ifstream fin("maxflow.in");
ofstream fout("maxflow.out");
int n,m,S,D,c[1005][1005],pt[1005],dist[1005];
vector<int> muchii[1005];
int ans;
const int INF=1e9;
int dfs(int nod,int cap)
{
    if(nod==D||cap==0)
        return cap;
    while(pt[nod]<muchii[nod].size())
    {
        int i=muchii[nod][pt[nod]];
        pt[nod]++;
        if(c[nod][i]>0&&dist[i]==dist[nod]+1)
        {
            int x=dfs(i,min(c[nod][i],cap));
            if(x!=0)
            {
                c[nod][i]-=x;
                c[i][nod]+=x;
                return x;
            }
        }
    }
    return 0;
}
int flux()
{
    for(int i=1;i<=n;i++)
    {
        pt[i]=0;
        dist[i]=-1;
    }
    dist[S]=0;
    queue<int> Q;
    Q.push(S);
    while(!Q.empty())
    {
        int nod=Q.front();
        Q.pop();
        for(auto i:muchii[nod])
            if(c[nod][i]>0&&dist[i]==-1)
            {
                dist[i]=dist[nod]+1;
                Q.push(i);
            }
    }
    if(dist[D]==-1)
        return 0;
    int val=0;
    while(true)
    {
        int x=dfs(S,INF);
        val+=x;
        if(x==0)
            break;
    }
    if(val==0)
        return 0;
    ans+=val;
    return 1;
}
int main()
{
    ios_base::sync_with_stdio(false);
    fin.tie(0);
    fout.tie(0);
    fin>>n>>m;
    S=1;
    D=n;
    for(int i=1;i<=m;i++)
    {
        int a,b;
        fin>>a>>b;
        fin>>c[a][b];
        muchii[a].push_back(b);
        muchii[b].push_back(a);
    }
    while(flux());
    fout<<ans;
    return 0;
}