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Cod sursa(job #445089)
#include <cstdio>
#include <vector>
#include <bitset>
using namespace std;
#define MAX 50005
#define INF 0x3f3f3f3f
#define min(a,b) (((a)<(b))?(a):(b))
int n,m,heap[MAX],poz[MAX],d[MAX],l;
vector<pair<int,int> > g[MAX];
bitset<MAX> viz;
void swapH(int a,int b)
{
int aux=heap[a];
heap[a]=heap[b];
heap[b]=aux;
poz[heap[a]]=a;
poz[heap[b]]=b;
}
void upHeap(int k)
{
while( (k>>1) && d[heap[k>>1]]>d[heap[k]] )
{
swapH(k,k>>1);
k>>=1;
}
}
void downHeap(int p)
{
int q=0;
while(q!=p)
{
q=p;
int x=q<<1;
for (int i=0; i<=1; i++,x++)
if(x<=l && d[heap[x]] < d[heap[p]] ) p=x;
swapH(p,q);
}
}
void dijkstra()
{
for(int i=1;i<=n;i++)
{
d[i]=INF;
heap[i]=poz[i]=i;
}
d[1]=0,l=n;
while(l)
{
int top=heap[1];
viz[heap[1]]=true;
swapH(1,l);
l--;
downHeap(1);
for(vector<pair<int,int> >::iterator it=g[top].begin();it!=g[top].end();it++)
{
if(!viz[it->first]&&(d[it->first]>d[top]+it->second))
{
d[it->first]=d[top]+it->second;
upHeap(poz[it->first]);
}
}
}
}
int main()
{
FILE* fin=fopen("dijkstra.in","r");
FILE* fout=fopen("dijkstra.out","w");
fscanf(fin,"%d %d\n",&n,&m);
int x,y,c;
for(int i=0;i<=m;i++)
{
fscanf(fin,"%d %d %d\n",&x,&y,&c);
g[x].push_back(make_pair(y,c));
}
dijkstra();
for(int i=2;i<=n;i++)
fprintf(fout,"%d ",(d[i]==INF)?0:d[i]);;
return 0;
}