Cod sursa(job #3205073)

Utilizator danutbodbodnariuc danut danutbod Data 18 februarie 2024 18:50:55
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.23 kb
#include <fstream>
#include <queue>
#include <vector>
#define dim 50002
#define inf 1e9
using namespace std;
ifstream cin("dijkstra.in");
ofstream cout("dijkstra.out");

int n,m;
int d[dim],sel[dim];
vector<pair<int,int>>a[dim];  //a[x] are muchii  (x,y) <y,cost>

struct comp{
    bool operator()(int a,int b){
        return d[a]>d[b];
    }
};

priority_queue<int,vector<int>,comp>Q;   // min heap Q (trebuie 3 parametrila folosirea comp!)>
                                         //un  min heap cu nodurile dupa d[]
void dijkstra(){
    for(int i=2;i<=n;++i) d[i]=inf;
    sel[1]=1;
    Q.push(1);
    while(!Q.empty()){
        int nod=Q.top();
        sel[nod]=0;
        Q.pop();
        for(auto v:a[nod]){
            int vecin=v.first;
            int cost=v.second;
            if(d[vecin]>cost+d[nod]){
               d[vecin]=cost+d[nod];
                if(!sel[vecin]) Q.push(vecin),sel[vecin]=1;
            }
        }
    }
}

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

    dijkstra();

    for(int i=2;i<=n;++i)
        if(d[i]!=inf) cout<<d[i]<<" ";
        else cout<<0<<" ";
    return 0;
}