Cod sursa(job #2254908)

Utilizator zdavid112zIon David-Gabriel zdavid112z Data 6 octombrie 2018 10:23:20
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.41 kb
#include <bits/stdc++.h>

using namespace std;

struct arc
{
    int nod, cost;
    bool operator<(const arc& a) const
    {
        return cost > a.cost;
    }
};
int lh; /// ultima pos ocupata
vector<arc> g[50005];
int dist[50005];

int n;

int main()
{
    freopen("dijkstra.in", "r", stdin);
    freopen("dijkstra.out", "w", stdout);
    int m, a, b, c;
    scanf("%d%d", &n, &m);
    while(m--)
    {
        scanf("%d%d%d", &a, &b, &c);
        g[a].push_back({b, c});
    }
    vector<arc> h;
    memset(dist, 0x3f, sizeof(dist));
    dist[1] = 0;
    for(int i = 0; i < g[1].size(); i++)
    {
        h.push_back(g[1][i]);
        dist[g[1][i].nod] = g[1][i].cost;
        push_heap(h.begin(), h.end());
    }
    while(!h.empty())
    {
        arc a = h[0];
        pop_heap(h.begin(), h.end());
        h.pop_back();
        if(a.cost != dist[a.nod])
            continue;
        for(int i = 0; i < g[a.nod].size(); i++)
        {
            if(dist[g[a.nod][i].nod] > a.cost + g[a.nod][i].cost)
            {
                dist[g[a.nod][i].nod] = a.cost + g[a.nod][i].cost;
                arc na = g[a.nod][i];
                na.cost += a.cost;
                h.push_back(na);
                push_heap(h.begin(), h.end());
            }
        }
    }
    for(int i = 2; i <= n; i++)
        printf("%d ", dist[i] == 0x3f3f3f3f ? 0 : dist[i]);
    return 0;
}