Cod sursa(job #2502515)

Utilizator CalarisPredut Denis Stefanita Calaris Data 30 noiembrie 2019 23:10:32
Problema Algoritmul lui Dijkstra Scor 50
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.09 kb
#include <cstdio>

const int maxn = 50001;
const int inf = 1 << 30;

FILE *in = fopen("dijkstra.in", "r"), *out = fopen("dijkstra.out", "w");

struct graf
{
	int nod, cost;
	graf *next;
};

int n, m;
graf *a[maxn];
int d[maxn], q[maxn];

void add(int where, int what, int cost)
{
	graf *q = new graf;
	q->nod = what;
	q->cost = cost;
	q->next = a[where];
	a[where] = q;
}

void read()
{
	fscanf(in, "%d %d", &n, &m);

	int x, y, z;
	for (int i = 1; i <= m; ++i)
	{
		fscanf(in, "%d %d %d", &x, &y, &z);
		add(x, y, z);
	}
}

void dijkstra()
{
	for (int i = 2; i <= n; ++i)
		d[i] = inf;

	int min, pmin = 0;
	for (int i = 1; i <= n; ++i)
	{
		min = inf;

		for (int j = 1; j <= n; ++j)
			if (d[j] < min && !q[j])
				min = d[j], pmin = j;

		q[pmin] = 1;

		graf *t = a[pmin];

		while (t)
		{
			if (d[t->nod] > d[pmin] + t->cost)
				d[t->nod] = d[pmin] + t->cost;

			t = t->next;
		}
	}
}

int main()
{
	read();
	dijkstra();

	for (int i = 2; i <= n; ++i)
		fprintf(out, "%d ", d[i] == inf ? 0 : d[i]);
	fprintf(out, "\n");

	return 0;
}