Cod sursa(job #2592974)

Utilizator mihaimodiMihai Modi mihaimodi Data 2 aprilie 2020 17:47:10
Problema Flux maxim Scor 60
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.59 kb
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream fin("maxflow.in");
ofstream fout("maxflow.out");
vector<int> g[1001];
queue<int> q;
int tata[1001];
int f[1001][1001],c[1001][1001];
bool viz[1001];
int sol,n,m,x,y;
int bfs()
{
    q.push(1);
    viz[1]=1;
    for(int i=1;i<=n;i++)
        tata[i]=viz[i]=0;
    while(!q.empty())
    {
        int nod=q.front();
        q.pop();
        for(int i=0;i<g[nod].size();i++)
        {
            int nou=g[nod][i];
            if(viz[nou]==0&&c[nod][nou]-f[nod][nou]>0)
            {
                viz[nou]=1;
                tata[nou]=nod;
                q.push(nou);
            }
        }
    }
    return viz[n];
}
int minim(int nod)
{
    int Min=c[nod][n];
    while(nod!=1)
    {
        int nou=tata[nod];
        Min=min(Min,c[nou][nod]-f[nou][nod]);
        nod=nou;
    }
    return Min;
}
void add(int val,int nod)
{
    f[nod][n]+=val;
    f[n][nod]-=val;
    while(nod!=1)
    {
        int nou=tata[nod];
        f[nou][nod]+=val;
        f[nod][nou]-=val;
        nod=nou;
    }
}
int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
        fin>>c[x][y];
    }
    while(bfs()==1)
        for(int i=0;i<g[n].size();i++)
        {
            int nod=g[n][i];
            if(c[nod][n]==f[nod][n]||viz[nod]==0)
                continue;

            int qmin=minim(nod);
            sol+=qmin;
            add(qmin,nod);

        }
    fout<<sol;
    return 0;
}