Cod sursa(job #2874854)

Utilizator rareshinnhoMiroiu Rares rareshinnho Data 20 martie 2022 12:59:36
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.55 kb
#include <bits/stdc++.h>

using namespace std;
ifstream fin("maxflow.in");
ofstream fout("maxflow.out");
int n,m,c[1001][1001],f[1001][1001],t[1001],Fmax;
vector<int> v[1001];

int bfs()
{
    queue<int> q;
    memset(t,0,sizeof(t));
    t[1]=-1;
    q.push(1);
    while(!q.empty())
    {
        int nod=q.front();
        q.pop();
        if(nod==n)return 1;
        for(int i=0;i<v[nod].size();i++)
        {
            int next=v[nod][i];
            if(t[next]==0&&f[nod][next]!=c[nod][next])
            {
                t[next]=nod;
                q.push(next);
            }
        }
    }
    return 0;
}

int main()
{
    int x,y,cost;
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y>>cost;
        v[x].push_back(y);
        v[y].push_back(x);
        c[x][y]=cost;
    }
    while(bfs())
    {
        for(int i=0;i<v[n].size();i++)
        {
            int nod=v[n][i];
            if(t[nod]&&f[nod][n]!=c[nod][n])
            {
                int FC=c[nod][n]-f[nod][n];
                for(int j=nod;j!=1;j=t[j])
                {
                    FC=min(FC,c[t[j]][j]-f[t[j]][j]);
                }
                if(FC)
                {
                    Fmax+=FC;
                    f[nod][n]+=FC;
                    f[n][nod]-=FC;
                    for(int j=nod;j!=1;j=t[j])
                    {
                        f[t[j]][j]+=FC;
                        f[j][t[j]]-=FC;
                    }
                }
            }
        }
    }
    fout<<Fmax;
}