Cod sursa(job #3297975)

Utilizator M132M132 M132 M132 Data 25 mai 2025 13:17:57
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.76 kb
#include <iostream>
#define FIN "dijkstra.in"
#define FOUT "dijkstra.out"
#include <vector>
#include <queue>
#include <limits>
#define MAX_NODES 50050
#define INF std::numeric_limits<int>::max()

using namespace std;

vector<int> V[MAX_NODES];
vector<int> C[MAX_NODES];

int distMin[MAX_NODES];

void read_graph(int& nodes, int& edges) {

     freopen(FIN,"r",stdin);

     cin>>nodes>>edges;

     for(int edge = 1; edge <= edges; ++edge) {


          int x, y, cost;
          cin>>x>>y>>cost;

          V[x].push_back(y);
          C[x].push_back(cost);
       }
}

void dijkstra(int startNode, int nodes) {

  for(int i = 2; i <= nodes; ++i) distMin[i] = INF;

  distMin[ startNode ] = 0;

  priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> pq;

  pq.push({0, startNode});

  while(!pq.empty()) {

        int currDist = pq.top().first;

        int currNode = pq.top().second;

        pq.pop();

        if(currDist > distMin[currNode]) continue;

        for(int i = 0; i < V[currNode].size(); ++i) {

            int nextNode = V[currNode][i];

            int cost = C[currNode][i];

            if(distMin[nextNode] > distMin[currNode] + cost) {

              distMin[nextNode] = distMin[currNode] + cost;

              pq.push({distMin[nextNode], nextNode});
            }
        }
  }

}

void  printShortestDistances(int nodes) {

      freopen(FOUT, "w", stdout);

      for(int i = 2; i <= nodes; ++i) {

          cout<<(distMin[i] < INF ? distMin[i] : 0) << " ";
      }

      cout<<endl;
}

int main(int argc, char const *argv[]) {

  int nodes, edges;

  read_graph(nodes, edges);

  dijkstra(1, nodes);

  printShortestDistances(nodes);

  return 0;
}