Cod sursa(job #2973060)

Utilizator IanisOpritescuOpritescu Ianis IanisOpritescu Data 30 ianuarie 2023 21:33:44
Problema Algoritmul lui Dijkstra Scor 60
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.26 kb
#include <fstream>
#include <iostream>
#include <vector>
#include <queue>
#include <utility>

using namespace std;

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

using PI = pair<int , int>;

const int INF = 1e7;
const int NN = 50001;
int n, m;
vector <PI> G[NN];
int dist[NN];

void dijkstra()
{
    priority_queue< PI> que;
    for(int i=1; i<=n; i++)
        dist[i] = INF;

    dist[1] = 0;
    que.push({dist[1], 1});

    while(!que.empty())
    {
        int x = que.top().first; // cost
        int y = que.top().second; // nod

        que.pop();

        if(x > dist[y])
            continue;

        for(size_t u = 0; u < G[y].size(); u ++)
        {
            int nodnou = G[y][u].first;
            int costnou = G[y][u].second;

            if(dist[nodnou] > dist[y] + costnou)
            {
               dist[nodnou] = dist[y] + costnou;
               que.push({dist[nodnou] , nodnou});
            }
        }
    }
}

int main()
{
    fin >> n >> m;
    for(int i=1; i<=m; i++)
    {
        int x, y, c;
        fin >> x >> y >> c;
        G[x].push_back({y, c});
    }

    dijkstra();

    for(int i=2; i<=n; i++)
        fout << (dist[i] == INF ? 0 : dist[i]) << " ";

    return 0;
}