Pagini recente » Cod sursa (job #2700430) | Cod sursa (job #2706793) | Cod sursa (job #1110381) | Cod sursa (job #837860) | Cod sursa (job #2758453)
#include <fstream>
#include <vector>
using namespace std;
const int N = 50001;
const int INF = 1e9 + 1;
struct succesor
{
int vf, c;
};
int d[N], h[N], poz[N], n, m, nh;
vector <succesor> s[N];
void schimba(int p, int q)
{
swap(h[p], h[q]);
poz[h[p]] = p;
poz[h[q]] = q;
}
void urca(int p)
{
while (p > 1 && d[h[p]] < d[h[p/2]])
{
schimba(p, p/2);
p /= 2;
}
}
void coboara(int p)
{
int fs = 2*p, fd = 2*p + 1, optim = p;
if (fs <= nh && d[h[fs]] < d[h[optim]])
{
optim = fs;
}
if (fd <= nh && d[h[fd]] < d[h[optim]])
{
optim = fd;
}
if (optim != p)
{
schimba(p, optim);
coboara(optim);
}
}
void sterge(int p)
{
if (p == nh)
{
nh--;
}
else
{
schimba(p, nh);
nh--;
urca(p);
coboara(p);
}
}
void dijkstra(int x0)
{
for (int i = 1; i <= n; i++)
{
d[i] = INF;
h[++nh] = i;
poz[i] = nh;
}
d[x0] = 0;
urca(poz[x0]);
while (nh > 0)
{
int x = h[1];
sterge(1);
for (auto p: s[x])
{
int y = p.vf;
int c = p.c;
if (d[x] + c < d[y])
{
d[y] = d[x] + c;
urca(poz[y]);
}
}
}
}
int main()
{
ifstream in("dijkstra.in");
ofstream out("dijkstra.out");
in >> n >> m;
for (int i = 0; i < m; i++)
{
int x, y, c;
in >> x >> y >> c;
s[x].push_back((succesor){y, c});
}
in.close();
dijkstra(1);
for (int i = 2; i <= n; i++)
{
if (d[i] == INF)
{
d[i] = 0;
}
out << d[i] << " ";
}
out.close();
return 0;
}