Cod sursa(job #2732970)

Utilizator rarestudurTudur Rares rarestudur Data 29 martie 2021 17:35:47
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.28 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

const int N = 50001;
const int INF = 1e9 + 100;

vector <pair <int,int>> a[N];
priority_queue <pair <int,int>> pq;
int d[N],n,m;
bool este_prelucrat[N];

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

void dijkstra(int x0)
{
    //initializez d
    for(int i = 1; i <= n; i++)
    {
        d[i] = INF;
    }
    d[x0] = 0;
    pq.push({-d[x0],x0});
    while(!pq.empty())
    {
        int x = pq.top().second;
        pq.pop();
        if(este_prelucrat[x])
        {
            continue;
        }
        //actualizam distantele fata de succesorii lui x
        for(auto p:a[x])
        {
            int y = p.first;
            int c = p.second;
            if(d[x] + c < d[y])
            {
                d[y] = d[x] + c;
                pq.push({-d[y],y});
            }
        }
    }
}

int main()
{
    in >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int x,y,c;
        in >> x >> y >> c;
        a[x].push_back({y,c});
    }
    dijkstra(1);
    for(int i = 2; i <= n; i++)
    {
        if(d[i] == INF)
        {
            d[i] = 0;
        }
        out << d[i] << " ";
    }
    in.close();
    out.close();
    return 0;
}