Pagini recente » Cod sursa (job #375666) | Cod sursa (job #1747303) | Cod sursa (job #98258) | Cod sursa (job #419819) | Cod sursa (job #1339951)
// Dijkstra - O(MlogN)
#include <fstream>
#include <vector>
#include <queue>
#include <bitset>
#define Nmax 50009
#define oo 2000000000
using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
int N,M,S,F,d[Nmax],x,y,ante[Nmax];
bitset < Nmax > inPQ;
struct muchie
{
int nod,c;
}aux;
vector < muchie > Graph[Nmax];
struct cmp
{
bool operator()(int x, int y)
{
if(d[x] > d[y]) return 1;
return 0;
}
};
priority_queue < int , vector < int > , cmp > pq;
void Dijkstra(int S)
{
for(int i=1;i<=N;++i)d[i]=oo,ante[i]=oo;
d[S]=ante[S]=0;
pq.push(S);
while(!pq.empty())
{
int node=pq.top();
pq.pop();
inPQ[node]=0;
for(vector<muchie>::iterator it=Graph[node].begin() ; it!=Graph[node].end() ; ++it)
if(d[node]+it->c < d[it->nod])
{
d[it->nod]=d[node]+it->c;
ante[it->nod]=node;
if(inPQ[it->nod]==0) {
pq.push(it->nod);
inPQ[it->nod]=1;
}
}
}
for (int i=1; i<=N; ++i)
if (d[i]==oo)d[i]=0,ante[i]=0;
}
void Rebuild(int node)
{
if(node==S){ g<<S<<' '; return; }
Rebuild(ante[node]);
g<<node<<' ';
}
int main()
{
f>>N>>M; S=1; F=N;
for(int i=1;i<=M;++i)
{
f>>x>>aux.nod>>aux.c;
Graph[x].push_back(aux);
/*
f>>x>>y>>c;
aux.nod=y; aux.c=c;
Graph[x].push_back(aux);
aux.nod=x; aux.c=c;
Graph[y].push_back(aux);
*/
}
Dijkstra(S);
for(int i=2; i<=N; i++)g<<d[i]<< ' ';
g<<'\n';
f.close();g.close();
return 0;
g<<"Drumul de la "<<S<< " la "<<F<<" are lungimea "<<d[F]<<"\n"; g<<"si este:\n";
Rebuild(F);
g<<'\n';
f.close();g.close();
return 0;
}