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Cod sursa(job #153299)
#include <stdio.h>
#define NMAX 50005
#define INF 1 << 30
int N, M, nh;
int d[NMAX], h[NMAX], poz[NMAX];
struct nod
{
int v, cost;
nod *next;
};
nod *m[NMAX];
void adaug(int a, int b, int c)
{
nod *aux;
aux = new nod;
aux -> v = b;
aux -> cost = c;
aux -> next = m[a];
m[a] = aux;
}
void swap(int i, int j)
{
int aux;
aux = h[i];
h[i] = h[j];
h[j] = aux;
poz[h[i]] = i;
poz[h[j]] = j;
}
void HeapUp(int k)
{
int t;
if ( k <= 1) return;
t = k >> 1;
if ( d[h[t]] > d[h[k]])
{
swap(t, k);
HeapUp(t);
}
}
void HeapDw(int k)
{
int st, dr, i, l;
l = k << 1;
if ( l <= nh)
{
st = h[ l ];
if ( (l | 1) <= nh)
dr = h[ l | 1];
else
dr = st - 1;
if ( st > dr)
i = l;
else
i = l | 1;
if ( d[h[i]] < d[h[k]] )
{
swap(i, k);
HeapDw(i);
}
}
}
int main()
{
int i, a, b, c, min;
nod *p;
freopen("dijkstra.in", "r", stdin);
freopen("dijkstra.out", "w", stdout);
scanf("%d %d", &N, &M);
for ( i = 1; i <= M; i++)
{
scanf("%d %d %d", &a, &b, &c);
adaug(a, b, c);
}
for ( i = 2; i <= N; i++)
{
d[i] = INF;
poz[i] = -1;
}
h[1] = 1;
poz[1] = 1;
nh = 1;
while ( nh )
{
min = h[1];
swap(1, nh);
poz[h[nh]] = -1;
nh--;
HeapDw(1);
for ( p = m[min]; p; p = p -> next)
if ( d[ p -> v] > d[min] + p -> cost)
{
d[ p -> v] = d[min] + p -> cost;
if ( poz[p->v] == -1)
{
nh++;
h[nh] = p -> v;
poz[p-> v] = nh;
}
HeapUp( poz[p->v] );
}
}
for ( i = 2; i <= N; i++)
printf("%d ", d[i] == INF ? 0 : d[i]);
return 0;
}