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Cod sursa(job #701534)
#include<fstream>
#include<algorithm>
#define maxn 50005
#define inf 1<<30
using namespace std;
struct graf
{
int nod,cost;
graf *next;
};
ifstream in("dijkstra.in");
ofstream out("dijkstra.out");
graf *a[maxn];
int h[maxn],poz[maxn],d[maxn];
int n,m,k;
int left_son(int nod)
{
return 2*nod;
}
int right_son(int nod)
{
return 2*nod+1;
}
void upheap(int nod)
{
while(nod/2>0 && d[h[nod]]<d[h[nod/2]])
{
swap(poz[h[nod]],poz[h[nod/2]]);
swap(h[nod],h[nod/2]);
nod/=2;
}
}
void downheap(int nod)
{
int son=0;
do
{
son=0;
if(left_son(nod)<=k)
son=left_son(nod);
if(right_son(nod)<=k && d[h[left_son(nod)]]>d[h[right_son(nod)]] )
son=right_son(nod);
if(d[h[son]]>d[h[nod]]) son=0;
if(son)
{
swap(poz[h[son]],poz[h[nod]]);
swap(h[son],h[nod]);
nod=son;
}
}while(son);
}
void dijkstra()
{
for(int i=1;i<=n;i++)
d[i]=inf,poz[i]=-1;
d[1]=0;
k=1;
poz[1]=1;
h[1]=1;
while(k)
{
int min=h[1];
h[1]=h[k];
k--;
poz[h[1]]=1;
downheap(1);
graf *t=a[min];
while(t)
{
if(d[t->nod]>t->cost+d[min])
{
d[t->nod]=t->cost+d[min];
if(poz[t->nod]==-1)
{
h[++k]=t->nod;
poz[t->nod]=k;
upheap(k);
}
else
upheap(poz[t->nod]);
}
t=t->next;
}
}
}
void add(int where,int what,int cost)
{
graf *q=new graf;
q->nod=what;
q->cost=cost;
q->next=a[where];
a[where]=q;
}
void read()
{
in>>n>>m;
int x,y,z;
for(int i=1;i<=m;i++)
{
in>>x>>y>>z;
add(x,y,z);
}
}
int main()
{
read();
dijkstra();
for(int i=2;i<=n;i++)
if(d[i]==inf) out<<"0 ";
else
out<<d[i]<<" ";
}