Cod sursa(job #2133972)

Utilizator inquisitorAnders inquisitor Data 17 februarie 2018 15:07:36
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.57 kb
#include <cstdio>
#include <list>
#include <queue>
using namespace std;

struct edge{
    int v, weight;

    edge(int _v, int _w){
        v = _v;
        weight = _w;
    }
};

struct compare{
    bool operator()(edge &x, edge &y){
        return x.weight > y.weight;
    }
};

int vertices, edges, u, v, weight;
int dist[50001]; bool visited[50001];
const int infinity = 25000001;
list<edge> adj[50001];

void Dijkstra(int source){

    for(int node = 1; node <= vertices; node++){
        dist[node] = infinity;
    }dist[source] = 0;

    priority_queue<edge, vector<edge>, compare> Q;
    Q.push(edge(source, dist[source]));

    while(Q.empty() == false){

        int u = Q.top().v; Q.pop();

        if(visited[u] == false){
            visited[u] = true;

            for(list<edge>::iterator it = adj[u].begin(); it != adj[u].end(); it++){

                int v = it -> v;
                int weight = it -> weight;

                if(dist[v] > dist[u] + weight){
                    dist[v] = dist[u] + weight;
                    Q.push(edge(v, dist[v]));
                }
            }
        }
    }
}

int main(){

    freopen("dijkstra.in", "r", stdin);
    freopen("dijkstra.out", "w", stdout);

    scanf("%d %d", &vertices, &edges);

    for(int i = 1; i <= edges; i++){
        scanf("%d %d %d", &u, &v, &weight);
        adj[u].push_back(edge(v, weight));
    }Dijkstra(1);

    for(int node = 2; node <= vertices; node++){
        printf("%d ", (dist[node] == infinity) ? 0 : dist[node]);
    }
    return 0;
}