Cod sursa(job #1654641)

Utilizator DanBrezeanuBrezeanu Dan DanBrezeanu Data 17 martie 2016 12:24:37
Problema Algoritmul lui Dijkstra Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.46 kb
#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

const int NMAX = 50003;
const int INF = 1<<20;

class Compare
{
public:
    bool operator () (int a , int b)
    {
        return (a>b);
    }
};

bool viz[NMAX];
vector<int>G[NMAX];
vector<int>dist[NMAX];
int discovered_distance[NMAX];


priority_queue<int , vector<int> , Compare> pq;

int n,m;

void Dijk(int u)
{
    int new_dist;

    pq.push(u);
    viz[u] = 1;
    discovered_distance[u] = 0;

    while(!pq.empty())
    {
        u = pq.top();
        pq.pop();

        for(size_t i=0;i<G[u].size();++i)
        {
            new_dist =  discovered_distance[u] + dist[u][i];

            if(new_dist < discovered_distance[G[u][i]])
            {
                discovered_distance[G[u][i]] = new_dist;
                pq.push(G[u][i]);
                viz[G[u][i]] = 1;
            }
        }
    }
}

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

    int pos1,pos2,d;

    scanf("%d%d",&n,&m);

    for(int i=1;i<=m;++i)
    {
        scanf("%d%d%d",&pos1,&pos2,&d);

        G[pos1].push_back(pos2);
        dist[pos1].push_back(d);

    }

    for(int i=1;i<=n;++i)
        discovered_distance[i] = INF;

    Dijk(1);

    for(int i=2;i<=n;++i)
        printf("%d ",discovered_distance[i] == INF ? 0 : discovered_distance[i]);

        printf("\n");

        return 0;
}