Pagini recente » Cod sursa (job #668271) | Cod sursa (job #2324176) | Cod sursa (job #1663996) | Cod sursa (job #137588) | Cod sursa (job #1916504)
#include <fstream>
#include<climits>
using namespace std;
ifstream cin ("dijkstra.in");
ofstream cout ("dijkstra.out");
struct bla
{
int nod,urm,cost;
} t[500010];
int n,m,w;
int start[50010];
int heap[500010];
int d[50010];
void read ()
{ int a,b,c,k=0;
cin>>n>>m;
for(int i=1;i<=m;++i)
{
cin>>a>>b>>c;
t[++k].nod=b; t[k].urm=start[a]; start[a]=k; t[k].cost=c;
}
}
void climb (int poz)
{
int key=heap[poz];
while(3>2)
{
if(poz>1 && d[key]<d[heap[poz/2]])
heap[poz]=heap[poz/2],poz/=2;
else { heap[poz]=key; break; }
}
}
void down (int poz)
{ int key=heap[poz];
while(3>2)
{
int fiu=0;
if(poz*2<=w) fiu=poz*2;
if(poz*2+1<=w && d[heap[fiu+1]]<d[heap[fiu]]) fiu++;
if(fiu && d[key]>d[heap[fiu]])
heap[poz]=heap[fiu],poz=fiu;
else { heap[poz]=key; break; }
}
}
void dijkstra ()
{
heap[++w]=1;
while(w)
{
int varf=heap[1];
for(int x=start[varf];x;x=t[x].urm)
if(d[varf]+t[x].cost<d[t[x].nod])
{
d[t[x].nod]=d[varf]+t[x].cost;
heap[++w]=t[x].nod;
climb(w);
}
heap[1]=heap[w--];
down(1);
}
}
void init ()
{
for(int i=2;i<=n;i++)
d[i]=INT_MAX;
}
void write ()
{
for(int i=2;i<=n;i++)
{
if(d[i]==INT_MAX) d[i]=0;
cout<<d[i]<<" ";
}
}
int main()
{
read();
init();
dijkstra();
write();
cin.close();
cout.close();
return 0;
}