Cod sursa(job #1881248)

Utilizator gabib97Gabriel Boroghina gabib97 Data 16 februarie 2017 12:02:11
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.14 kb
#include <stdio.h>
#include <vector>
#include <queue>
#define N 50001
#define inf 100000000
#define pp pair<int,int>
using namespace std;

int n,m,i,x,y,c,d[N];
vector<pp> G[N];
class comp
{
public:
    bool operator()(pp a,pp b)
    {
        return d[a.first]>d[b.first];
    }
};
priority_queue<pp, vector<pp>, comp > Q;

void dijkstra()
{
    int i,x;
    pp p;
    for (i=2;i<=n;i++) d[i]=inf;

    Q.push(make_pair(1,0));
    while (!Q.empty())
    {
        p=Q.top();
        Q.pop();
        x=p.first;
        if (d[x]!=p.second) continue;
        for (i=0;i<G[x].size();i++)
        {
            y=G[x][i].first;
            if (d[y]>d[x]+G[x][i].second)
            {
                d[y]=d[x]+G[x][i].second;
                Q.push(make_pair(y,d[y]));
            }
        }
    }
}
int main()
{
    freopen ("dijkstra.in","r",stdin);
    freopen ("dijkstra.out","w",stdout);
    scanf("%i%i",&n,&m);
    for (i = 1; i <= m; i++)
    {
        scanf("%i%i%i",&x,&y,&c);
        G[x].push_back(make_pair(y,c));
    }
    dijkstra();
    for (i=2;i<=n;i++)
        printf("%i ",d[i]==inf?0:d[i]);
    fclose(stdin);
    fclose(stdout);
    return 0;
}