Cod sursa(job #2670964)

Utilizator De_Azi_Ne_DopamAlex Ardelean De_Azi_Ne_Dopam Data 11 noiembrie 2020 02:25:44
Problema Flux maxim Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.9 kb
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
int C[1001][1001];
int tata[1001],n;
int coada[1001],viz[1001];
vector <int> v[1001];
int bfs()
{
    int u=-1,p=0;
    coada[++u]=1;
    viz[1]=1;
    while(p<=u)
    {
        int x=coada[p++];
        if(x!=n)
            for(auto it:v[x])
                if(C[x][it]&&!viz[it])
                {
                    coada[++u]=it;
                    tata[it]=x;
                    viz[it]=1;
                }
    }
    return viz[n];
}
void dfs(int nod,int papa)
{
    viz[nod]=1;
    for(auto it:v[nod])
        if(it!=papa&&!viz[it]&&C[nod][it])
            dfs(it,nod);
}
int main()
{
#ifndef HOME
    freopen("maxflow.in","r",stdin);
    freopen("maxflow.out","w",stdout);
#endif // HOME
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    int m,i,a,b,c;
    cin>>n>>m;
    for(i=1; i<=m; i++)
    {
        cin>>a>>b>>c;
        v[a].push_back(b);
        v[b].push_back(a);
        C[a][b]=c;
    }
    int sum=0;
    while(bfs())
    {
        for(auto it:v[n])
            if(viz[it]&&C[it][n])
            {
                int min1=1e9;
                tata[n]=it;
                for(int j=n; j!=1; j=tata[j])
                    min1=min(min1,C[tata[j]][j]);
                if(min1!=0)
                    for(int j=n; j!=1; j=tata[j])
                    {
                        C[tata[j]][j]-=min1;
                        C[j][tata[j]]+=min1;
                    }
                sum+=min1;
            }
        for(int i=1; i<=n; i++)
            viz[i]=0;
    }
    cout<<sum;
    /*dfs(1,0);
    sum=0;
    for(i=1;i<=n;i++)
        for(auto it:v[i])
            if(viz[i]&&!viz[it])
                sum+=C[i][it]+C[it][i];
    cout<<sum;*/
    return 0;
}