Cod sursa(job #3032414)

Utilizator rARES_4Popa Rares rARES_4 Data 22 martie 2023 09:39:57
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.99 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f ("maxflow.in");
ofstream g ("maxflow.out");
vector<int>adiacenta[1001];
bool viz[1001];
int capacitate[1001][1001];
int rasp_flux;
int n,m;
int tati[1001];
queue<int>q;
void init()
{
    for(int i =1; i<=n; i++)
    {
        viz[i] = 0;
        tati[i] = i;
    }
}
bool bfs()
{
    init();
    viz[1]=1;
    q.push(1);
    while(!q.empty())
    {
        int curent = q.front();
        q.pop();
        if(curent==n)
            continue;
        for(auto x:adiacenta[curent])
        {
            if(capacitate[curent][x]!=0 && viz[x]==0)
            {
                q.push(x);
                tati[x] = curent;
                viz[x] = 1;
            }
        }
    }
    if(viz[n]==0)
        return 0;
    else
        return viz[n];
}
int main()
{
    f >> n>> m;
    for(int i = 1; i<=m; i++)
    {
        int x,y,c;
        f >> x >> y>>c;
        adiacenta[x].push_back(y);
        adiacenta[y].push_back(x);
        capacitate[x][y] = c;
    }
    while(bfs())
    {
        for(auto x:adiacenta[n])
        {
            if(capacitate[x][n]!=0 &&viz[x])
            {
                int nod_start = n;
                int max_flux = (1<<30)-1;
                tati[n]=x;
                while(nod_start!=1)
                {
                    max_flux = min(max_flux,capacitate[tati[nod_start]][nod_start]);
                    nod_start=tati[nod_start];
                }
                nod_start = n;
                if(max_flux==0)
                    continue;
                rasp_flux +=max_flux;

                while(nod_start!=1)
                {
                    capacitate[tati[nod_start]][nod_start]-=max_flux;
                    capacitate[nod_start][tati[nod_start]]+=max_flux;
                    nod_start=tati[nod_start];
                }
            }
        }
    }
    g<<rasp_flux<< endl;
}