Cod sursa(job #1205126)

Utilizator IonMosnoiIon Mosnoi IonMosnoi Data 5 iulie 2014 13:09:05
Problema Flux maxim Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.56 kb
#include<fstream>
#include<vector>
#include<algorithm>
using namespace std;
ifstream f("maxflow.in");
ofstream o("maxflow.out");

const int inf = 1000000000;
vector <int> a[1007],b[1009];
int n,m, semn[1009],retea[1009][1009],flux[1009][1009],parc[1009],venit[1009],ok;

void df(int nod,int v,int ok1);

void marc(int nod,int tata,int v){
	 
		if(semn[nod]){
			flux[tata][nod]+=v;
		}else flux[nod][tata]-=v;
		
		if(tata==1){
			for(int i=1;i<=n;i++)parc[i]=0;
			ok++;
			df(1,inf,ok);
	   }else marc(tata,venit[tata],v);
	   	
}


void df(int nod,int v,int ok1){
	
	if(nod==n){
		marc(nod,venit[nod],v);
		ok=0;
		return;
	}
	parc[nod]=1;
	for(int i=0;i<a[nod].size();i++)
	  if(parc[a[nod][i]]!=1 && flux[nod][a[nod][i]]<retea[nod][a[nod][i]] && ok==ok1){
	  	 venit[a[nod][i]]=nod;
	  	 semn[a[nod][i]]=1;
	  	 df(a[nod][i],min(v,retea[nod][a[nod][i]]-flux[nod][a[nod][i]]),ok1);	  	 
	  }
	for(int i=0;i<b[nod].size();i++)
	  if(parc[b[nod][i]]!=1 && flux[b[nod][i]][nod]>0 && ok==ok1){
	  	 venit[b[nod][i]]=nod;
	  	 semn[b[nod][i]]=0;
	  	 df(b[nod][i],min(v,flux[b[nod][i]][nod]),ok1);	  	 
	  }	    
	
}

int main(){
	f>>n>>m;
	int x,y,z;
	for(int i=1;i<=m;i++){
		f>>x>>y>>z;
		retea[x][y]=z;
		a[x].push_back(y);
		b[y].push_back(x);
	}
	ok=1;
	df(1,inf,ok);
	int fl = 0;
	for(int i=1;i<=n;i++)fl+=flux[1][i];
/*	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=n;j++)o<<retea[i][j]<<" ";
		o<<endl;
	}
	o<<endl;
	
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=n;j++)o<<flux[i][j]<<" ";
		o<<endl;
	}*/
	o<<fl;
}