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Cod sursa(job #582980)
#include <cstdio>
#include <cstring>
#include <fstream>
#define Nmx 50001
#define INF 0x3f3f3f3f
using namespace std;
int n,m,Heap[Nmx],nr,poz[Nmx],cost[Nmx];
struct nod
{
int inf,c;
nod *urm;
};
nod *G[Nmx];
ifstream fin("dijkstra.in");
void add(int x,int y,int c)
{
nod *aux=new nod;
aux->inf = y;
aux->c = c ;
aux->urm = G[x];
G[x] = aux;
}
void read()
{
int x,y,c;
fin>>n>>m;
for(int i=1;i<=m;++i)
{
fin>>x>>y>>c;
add(x,y,c);
}
}
void up(int k)
{
while(k>1&&cost[Heap[k/2]]>cost[Heap[k]])
{
int aux=Heap[k/2];
Heap[k/2]=Heap[k];
Heap[k]=aux;
poz[Heap[k]]=k/2;
poz[Heap[k/2]]=k;
k/=2;
}
}
void down(int k)
{
while(k*2<=nr)
{
int p=k*2;
if(p+1<=nr&&cost[Heap[p+1]]<cost[Heap[p]])
p=p+1;
int aux=Heap[p];
Heap[p]=Heap[k];
poz[Heap[p]]=k;
poz[Heap[k]]=p;
k=p;
}
}
void solve()
{
for(int i=1;i<=n;++i)
{
cost[i]=INF;
poz[i]=-1;
}
cost[1]=0;
poz[1]=1;
Heap[++nr]=1;
while(nr)
{
int x = Heap[1];
poz[Heap[nr]]=1;
poz[Heap[1]]=-1;
Heap[1]=Heap[nr--];
down(1);
for(nod *p=G[x];p;p=p->urm)
if(cost[p->inf]>cost[x]+p->c)
{
cost[p->inf]=cost[x]+p->c;
if(poz[p->inf]==-1)
{
Heap[++nr]=p->inf;
poz[p->inf]=nr;
up(nr);
}
else up(poz[p->inf]);
}
}
for(int i=2;i<=n;++i)
if(cost[i]==INF)
printf("0 ");
else printf("%d ",cost[i]);
printf("\n");
}
int main()
{
freopen("dijkstra.out","w",stdout);
read();
solve();
return 0;
}