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Cod sursa(job #144954)
#include <stdio.h>
#include <vector>
const int inf = 1 << 30;
using namespace std;
vector<int> v[50001], cost[50001];
int d[50001], h[50001], ph[50001], n, m;
void dijkstra(int);
void riseup(int);
void godown(int);
int main()
{
freopen("dijkstra.in", "r", stdin);
freopen("dijkstra.out", "w", stdout);
int i, a, b, c;
scanf("%d %d", &n, &m);
for(i = 1; i <= m; ++i)
{
scanf("%d %d %d", &a, &b, &c);
v[a].push_back(b);
cost[a].push_back(c);
}
dijkstra(1);
for(i = 2; i <= n; ++i)
{
if(d[i] == inf)
d[i] = 0;
printf("%d ", d[i]);
}
return 0;
}
void dijkstra(int nod)
{
int i, sz;
for(i = 1; i <= n; ++i)
{
d[i] = inf;
h[i] = ph[i] = i;
}
d[1] = 0;
h[0] = n;
while(h[0])
{
/*
for(i = 1; i <= h[0]; ++i)
{
printf("%d %d\n",h[i], d[h[i]]);
}
printf("\n");
*/
sz = v[h[1]].size();
for(i = 0; i < sz; ++i)
{
if(d[v[h[1]][i]] > d[h[1]] + cost[h[1]][i])
{
d[v[h[1]][i]] = d[h[1]] + cost[h[1]][i];
riseup(ph[v[h[1]][i]]);
}
}
h[1] = h[h[0]];
ph[h[1]] = 1;
--h[0];
godown(1);
}
}
void godown(int pos)
{
int l = pos << 1, r = l + 1, best = pos;
if(l <= h[0] && d[h[l]] < d[h[best]])
{
best = l;
}
if(r <= h[0] && d[h[r]] < d[h[best]])
{
best = r;
}
if(best != pos)
{
int temp;
temp = h[best];
h[best] = h[pos];
h[pos] = temp;
ph[h[pos]] = pos;
ph[h[best]] = best;
godown(best);
}
}
void riseup(int pos)
{
int dad = pos >> 1;;
if(dad)
{
if(d[h[pos]] < d[h[dad]])
{
int temp;
temp = h[pos];
h[pos] = h[dad];
h[dad] = temp;
ph[h[pos]] = pos;
ph[h[dad]] = dad;
riseup(dad);
}
}
}