Cod sursa(job #2838290)

Utilizator cdenisCovei Denis cdenis Data 23 ianuarie 2022 12:41:30
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <bitset>

using namespace std;

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

const int MAX=50005;
const int INF=2e9;
int n,m,a,b,c;
bitset < MAX > inq;
vector < int > dist (MAX, INF);
struct T
{
    int nod,dist;
};
struct cmp
{
    bool operator()(T a, T b)
    {
        return dist[a.nod]>dist[b.nod];
    }
};
vector < T > adj[MAX];
priority_queue < T, vector < T >, cmp > pq;

void dijkstra(int src)
{
    dist[src]=0;
    pq.push({src,0});
    while(!pq.empty())
    {
        int u=pq.top().nod;
        inq[u]=0;
        pq.pop();
        for(auto ngh : adj[u])
        {
            int v=ngh.nod;
            int weight=ngh.dist;
            if(dist[v]>dist[u]+weight)
            {
                dist[v]=dist[u]+weight;
                if(!inq[v])
                {
                    inq[v]=1;
                    pq.push({v,dist[v]});
                }
            }
        }
    }
}

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