Cod sursa(job #2905412)

Utilizator Coltan_CristianColtan Cristian Gabriel Coltan_Cristian Data 21 mai 2022 13:22:12
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 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;
}