Cod sursa(job #2133995)

Utilizator inquisitorAnders inquisitor Data 17 februarie 2018 15:23:15
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.44 kb
#include <bits/stdc++.h>

struct edge
{
    int v, cost;
};

int nodes, edges, u, v, cost;

std :: vector<edge> adj[50001];

int distance[50001], OO = (1 << 31) - 1;

bool visited[50001];

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

std :: priority_queue<edge, std :: vector<edge>, orderByDistance> Q;

void Dijkstra(int source)
{

    for(int i = 1; i <= nodes; i++)
    {
        distance[i] = OO;
    }

    distance[source] = 0;

    Q.push({source, distance[source]});

    while(!Q.empty())
    {
        int u = Q.top().v; Q.pop();

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

            for(edge i : adj[u])
            {
                int v = i.v, cost = i.cost;

                if(distance[v] > distance[u] + cost)
                {
                    distance[v] = distance[u] + cost;

                    Q.push({v, distance[v]});
                }
            }
        }
    }
}

int main(){

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

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

    for(int i = 1; i <= edges; i++)
    {
        scanf("%d %d %d", &u, &v, &cost);

        adj[u].push_back({v, cost});
    }

    Dijkstra(1);

    for(int i = 2; i <= nodes; i++)
    {
        printf("%d ", distance[i] == OO ? 0 : distance[i]);
    }
    return 0;
}