Cod sursa(job #2548571)

Utilizator alex02Grigore Alexandru alex02 Data 16 februarie 2020 20:07:02
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.26 kb
#include <iostream>
#include <queue>
#include <fstream>
#include <vector>

using namespace std;

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

int d[50005],n,m;
int infi=1<<30;
vector<pair<int,int>>G[50005];

struct comparator{
    bool operator() (int x, int y){
        return x<y;
    }
};

priority_queue<int,vector<int>,comparator> PQ;

void citire(){
    f>>n>>m;
    for(int i=0; i<m; i++){
        int x,y,c;
        f>>x>>y>>c;
        G[x].emplace_back(y,c);
    }
}
int inCoada[50005];

void rezolvare(int start){
    for(int i=1; i<=n; i++){
        d[i]=infi;
    }

    PQ.push(start);
    inCoada[start]=1;
    d[start]=0;

    while (!PQ.empty()){
        int nodCurent=PQ.top();
        PQ.pop();
        inCoada[nodCurent]=0;
        for(auto &v:G[nodCurent]){
            int vecin=v.first;
            int cost=v.second;
            if(d[nodCurent]+cost<d[vecin]){
                d[vecin]=d[nodCurent]+cost;
                if(inCoada[vecin]==0){
                    PQ.push(vecin);
                    inCoada[vecin]=1;
                }
            }
        }
    }

}

int main() {
    citire();
    rezolvare(1);
    for(int i=2; i<=n; i++){
        if(d[i]!=infi)
            g<<d[i]<<" ";
        else
            g<<0<<" ";
    }

    return 0;
}