Cod sursa(job #2884083)

Utilizator cdenisCovei Denis cdenis Data 2 aprilie 2022 13:05:03
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.34 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");

const int MAX=50005;
const int INF=1e9;
int n,m,a,b,c,dist[MAX],inq[MAX];
struct T
{
    int nod,cost;
};
vector < T > v[MAX];
struct cmp
{
    bool operator()(T a, T b)
    {
        return a.cost>b.cost;
    }
};
priority_queue < T, vector < T >, cmp > pq;

void dijkstra(int start)
{
    for(int i=1;i<=n;i++)
        dist[i]=INF;
    dist[start]=0;
    pq.push({start,0});
    inq[start]=1;
    while(!pq.empty())
    {
        int nod=pq.top().nod;
        inq[nod]=0;
        pq.pop();
        for(auto adj : v[nod])
        {
            int vec=adj.nod;
            int cost=adj.cost;
            if(dist[nod]+cost<dist[vec])
            {
                dist[vec]=dist[nod]+cost;
                if(!inq[vec])
                {
                    pq.push({vec,dist[vec]});
                    inq[vec]=1;
                }
            }
        }
    }
}

int main()
{
    fin >> n >> m;
    while(m--)
    {
        fin >> a >> b >> c;
        v[a].push_back({b,c});
    }
    dijkstra(1);
    for(int i=2;i<=n;i++)
        if(dist[i]==INF)
            fout << "0 ";
        else
            fout << dist[i] << " ";
    return 0;
}