Pagini recente » Profil DEYDEY2 | ONIS 2015, Solutii Runda 1 | Clasament prosoft2016-9 | Tudorica | Cod sursa (job #3040131)
#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
#include <queue>
///#include <tryhardmode>
///#include <GODMODE::ON>
using namespace std;
ifstream fin ("traseu.in");
ofstream fout ("traseu.out");
const int INF=2e9;
const int NMAX=500;
vector<pair<int,int>>v[NMAX];
int flux[NMAX][NMAX];
int dist[NMAX];
int t[NMAX];
int ti[NMAX];
int to[NMAX];
bool viz[NMAX];
int n,s,d;
int bellman()
{
int i;
for(i=0;i<=n+1;i++)
{
viz[i]=false;
dist[i]=INF;
}
queue<int>q;
q.push(s);
dist[s]=0;
viz[s]=true;
while(!q.empty())
{
int p=q.front();
q.pop();
viz[p]=false;
for(auto i:v[p])
{
if(flux[p][i.first]>0 && dist[i.first]>dist[p]+i.second)
{
dist[i.first]=dist[p]+i.second;
if(!viz[i.first])
{
q.push(i.first);
viz[i.first]=true;
}
t[i.first]=p;
}
}
}
return dist[d];
}
int main()
{
int m,i,j,x,y,cost,mini;
int maxi=0;
fin>>n>>m;
for(i=1;i<=m;i++)
{
fin>>x>>y>>cost;
maxi+=cost;
v[x].push_back(make_pair(y,cost));
v[y].push_back(make_pair(x,-cost));
flux[x][y]=INF;
ti[y]++;
to[x]++;
}
s=0;
d=n+1;
for(i=1;i<=n;i++)
{
if(ti[i]>to[i])
{
v[0].push_back(make_pair(i,0));
v[i].push_back(make_pair(0,0));
flux[0][i]=ti[i]-to[i];
}
if(ti[i]<to[i])
{
v[n+1].push_back(make_pair(i,0));
v[i].push_back(make_pair(n+1,0));
flux[i][n+1]=to[i]-ti[i];
}
}
while(true)
{
mini=INF;
int suma=bellman();
if(suma==INF)
break;
x=d;
while(x!=s)
{
mini=min(mini,flux[t[x]][x]);
x=t[x];
}
x=d;
while(x!=s)
{
flux[x][t[x]]+=mini;
flux[t[x]][x]-=mini;
x=t[x];
}
maxi=maxi+mini*suma;
}
fout<<maxi;
return 0;
}