Cod sursa(job #1996056)

Utilizator AlexandruRudiAlexandru Rudi AlexandruRudi Data 29 iunie 2017 20:05:41
Problema Flux maxim Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.51 kb
#include <bits/stdc++.h>
using namespace std;
#define x first
#define y second
#define dbg(x) cout << #x << '=' << x << '\n';
#define ll long long
#define pi pair<int,int>
#define pl pair<long long,long long>
#define rd(x) cin >> x;
#define rda(a,n) for(int i=1;i<=n;i++) cin >> a[i];
#define wr(x) cout << x << ' ';
#define wrl(x) cout << x << '\n';
#define wra(a,n) for(int i=1;i<=n;i++) cout << a[i] << ' '; cout << '\n';
#define lg length()
#define pb push_back
ifstream in("maxflow.in");
ofstream out("maxflow.out");
#define MAXN 100005
#define INF 1000000005
#define LINF 1000000000000000005

int n,m,c[1005][1005],f[1005][1005],v[1005],x,y,z,ans,p[1005];

vector <int> g[1005],t;

bool DFS(int nod){
    v[nod]=1;
    if(nod==n) return 1;
    for(int i : g[nod]){
        if(!(c[nod][i]-f[nod][i]) || v[i]) continue;
        p[i]=nod;
        if(DFS(i)) return 1;
    }
    return 0;
}

int32_t main(){
    ios_base :: sync_with_stdio(0);
    in >> n >> m;
    for(int i=1;i<=m;i++){
        in >> x >> y >> z;
        g[x].pb(y);
        g[y].pb(x);
        c[x][y]=z;
    }
    while(DFS(1)){
        for(int i : g[n]){
            if(!(c[i][n]-f[i][n]) || !v[i]) continue;
            int fl=1e9;
            p[n]=i;
            for(int j=n;j!=1;j=p[j]) fl=min(fl,c[p[j]][j]-f[p[j]][j]);
            if(fl==0) continue;
            for(int j=n;j!=1;j=p[j]) f[p[j]][j]+=fl,f[j][p[j]]-=fl;
            ans+=fl;
        }
        for(int i=1;i<=n;i++) v[i]=0;
    }
    out << ans;
}