Cod sursa(job #2860959)

Utilizator SebytomitaTomita Sebastian Sebytomita Data 3 martie 2022 11:27:53
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.88 kb
#include <fstream>
#include <iostream>
#include <vector>
#include <queue>
#define NMAX 100004
#define INF 100000000000
using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
struct varf
{
    int x, c;
};
long long int n, x0=1, m;
vector<varf> G[NMAX];
bool uz[NMAX];
long long int cmin[NMAX];
long long int poz[NMAX];

class Compar
{
public:
    bool operator() (int a, int b) ///a si b sunt doua varfuri
    {
        ///min heap
        return cmin[a]>cmin[b];
    }
};
priority_queue<long long int, vector<long long int>, Compar>H;
void citire();
void dijkstra();
void afisare();
int main()
{
    citire();
    dijkstra();
    afisare();
    return 0;
}
void citire()
{
    long long int i, j, c;
    varf aux;
    fin>>n>>m;
    while(fin>>i>>j>>c)
    {
        ///in lista de adiacenta a lui i  trb sa adaug perechea (j, c)
        aux.x=j;
        aux.c=c;
        G[i].push_back(aux);
    }
    for(i=1; i<=n; i++)
        cmin[i]=INF;
    cmin[x0]=0;
}
void dijkstra()
{
    long long int i, j, minim, vfmin,gasit;
    H.push(x0);

    ///calculez vfmin
    gasit=0;
    while(!H.empty())
    {
        vfmin=H.top();
        H.pop();
        if(!uz[vfmin])
        {
            uz[vfmin]=1;
            minim=cmin[vfmin];
            if(minim==INF)
            break;

        //uz[vfmin]=1;
        //minim=cmin[vfmin];
        ///optimizez eventual costurile minime
        for(j=0; j<G[vfmin].size(); j++)
            if(!uz[G[vfmin][j].x] && cmin[G[vfmin][j].x]>minim+G[vfmin][j].c)
            {
                cmin[G[vfmin][j].x]=minim+G[vfmin][j].c;
                H.push(G[vfmin][j].x);
            }
        }
    }
}
void afisare()
{
    long long int i, j, cnt;
    for(i=2; i<=n; i++)
        if(cmin[i]==INF)
            fout<<0<<' ';
        else
            fout<<cmin[i]<<' ';
}