Cod sursa(job #2297548)

Utilizator GeorgianBaditaBadita Marin-Georgian GeorgianBadita Data 5 decembrie 2018 23:26:39
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.45 kb
#include <fstream>
#include <vector>
#include <queue>
#define NMAX 50005
#define INF 1e9
#define pb push_back
using namespace std;

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

struct Node{
private:
    int y, cost;
public:
    Node(const int& y, const int& cost): y{y}, cost{cost} {}

    int get_y() const {
        return this->y;
    }

    int get_cost() const {
        return this->cost;
    }

    bool operator<(const Node& other) const {
        return  this->cost > other.get_cost();
    }
};
vector<Node> G[NMAX];
int n, m, dist[NMAX];
priority_queue<Node> pq;

void read_data(){
    in >> n >> m;
    for(int i = 1; i<=m; i++){
        int x, y, c;
        in >> x >> y >> c;
        G[x].pb({y, c});
    }
}


void dijkstra(){
    for(int i = 1; i<=n; i++){
        dist[i] = static_cast<int>(INF);
    }
    dist[1] = 0;
    pq.push({1, dist[1]});

    while(!pq.empty()){
        auto top = pq.top();
        pq.pop();
        if(top.get_cost() != dist[top.get_y()]){
            continue;
        }

        int node = top.get_y();
        for(const auto& adj : G[node]){
            if(dist[node] + adj.get_cost() < dist[adj.get_y()]){
                dist[adj.get_y()] = dist[node] + adj.get_cost();
                pq.push({adj.get_y(), dist[adj.get_y()]});
            }
        }
    }
}

int main(){
    read_data();
    dijkstra();
    for(int i = 2; i<=n; i++){
        dist[i] != INF ? out << dist[i] << ' ' : out << 0 << ' ';
    }
    return 0;
}