Cod sursa(job #2808867)

Utilizator FraNNNkieFrancesco-Gregorio Petrovici FraNNNkie Data 25 noiembrie 2021 16:40:47
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.41 kb
#include <fstream>
#include <queue>
#include <vector>
#define NMAX 50005

using namespace std;

int n, m;
int dist[NMAX];
bool inQueue[NMAX];

vector <pair <int, int> > la[NMAX];

struct cmp{
    bool operator()(int x, int y){
        return dist[x] > dist[y];
    }
};

priority_queue <int, vector <int>, cmp> q;

void dijkstra(int start){
    for(int i = 1; i <= n; ++i){
        dist[i] = INT_MAX;
        inQueue[i] = false;
    }
    dist[start] = 0;
    q.push(start);
    inQueue[start] = true;
    while(!q.empty()){
        int nod = q.top();
        q.pop();
        inQueue[nod] = false;
        for(unsigned int i = 0; i < la[nod].size(); ++i){
            int v = la[nod][i].first;
            int c = la[nod][i].second;
            if(dist[nod] + c < dist[v]){
                dist[v] = dist[nod] + c;
            }
            if(!inQueue[v]){
                q.push(v);
                inQueue[v] = true;
            }
        }
    }

}


int main()
{
    ifstream f("dijkstra.in");
    ofstream g("dijkstra.out");
    f >> n >> m;
    for(int i = 0; i < m; ++i){
        int a, b, c;
        f >> a >> b >> c;
        la[a].push_back(make_pair(b, c));
    }
    dijkstra(1);
    for(int i = 2; i <= n; ++i){
        if(dist[i] != INT_MAX){
            g << dist[i] << " ";
        }
        else{
            g << 0 << " ";
        }
    }
    return 0;
}