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Cod sursa(job #711554)
#include<stdio.h>
#define INF 1 << 30
#define N 50005
FILE *f=fopen("dijkstra.in","r"), *g=fopen("dijkstra.out","w");
int d[N], H[N], poz[N], el, n, m;
struct nod
{
int y, c;
nod *urm;
} *v[N];
void swap(int &a, int &b)
{
a=a^b;
b=a^b;
a=a^b;
}
void downheap(int k)
{
int son;
do
{
son=0;
if(k*2 <= el) son=k*2;
if(k*2+1 <=el && d[ H [k*2+1] ] < d[ H[k*2] ])
son= 2*k+1;
if( d[H[k]] < d[H[son]])
son=0;
if(son)
{
swap(H[k], H[son]);
poz[H[k]] = son;
poz[H[son]] = k;
}
k=son;
} while(son);
}
void upheap(int k)
{
int val=d[ H[k] ];
while(val < d[ H[ k/2 ]])
{
swap(H[k], H[k/2]);
swap(poz[H[k]], poz[H[k/2]]);
//poz[H[k]]= k/2;
//poz[H[k/2]]= k;
k=k/2;
}
}
void push(int x)
{
H[++el]=x;
poz[x]=el;
upheap(el);
}
void rez()
{
int min;
for(int i=1; i<=n;i++)
d[i]= INF;
for(nod *p=v[1]; p; p=p->urm)
{
d[ p->y ]= p->c;
push(p->y);
}
while(el)
{
min=d[ H[1] ];
for(nod *p=v[ H[1] ]; p; p=p->urm)
{
if( d[p->y] > p->c + min)
if(d[p->y]==INF)
{
d[p->y]= p->c+min;
H[++el]=p->y;
upheap(p->y);
}
else
{
d[p->y]= p->c+min;
upheap(poz[p->y]);
}
}
H[1]=H[el--];
downheap(1);
}
}
void add(int x, int y, int c)
{
nod *p=new nod;
p->c=c;
p->y=y;
p->urm=v[x];
v[x]=p;
}
int main()
{
int a, b, c;
fscanf(f,"%d %d", &n, &m);
for(int i=1;i<=m;i++)
{
fscanf(f,"%d %d %d", &a, &b, &c);
add(a,b,c);
}
rez();
for(int i=2;i<=n;i++)
if(d[i]!=INF)
fprintf(g,"%d ", d[i]);
else
fprintf(g,"%d ", 0);
return 0;
}