Cod sursa(job #3192799)

Utilizator v_mateiVatamanu Matei v_matei Data 13 ianuarie 2024 11:18:51
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.67 kb
#include <fstream>
#include <vector>
#include<queue>
#define NMAX 100005
#define INF 1000000002

using namespace std;

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

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

int n, p = 1, cmin[NMAX], m, x, c;
int vfmin;
int i, j;
int uz[NMAX];
class ComparVf{
public:
    bool operator ()(int x, int y){
        return cmin[x] > cmin[y];
    }
};

priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>> > H;


void citire(){
    fin >> n >> m;
    int i, j, c;
    pair<int, int> vf;
    while(fin >> i >> j >> c){
            vf.first = j; vf.second = c;
            g[i].push_back(vf);
    }
}

void djikstra(){
    pair<int, int> pp;
    pp.first = 0 ;
    pp.second = p;
    H.push(pp);

    for(i = 1; i <= n; i++){
        cmin[i] = INF;
    }
    cmin[p] = 0;


    while(!H.empty()){
        vfmin = H.top().second;
        H.pop();
        if(cmin[vfmin] == INF) break;
        if(!uz[vfmin]){
            for(i = 0; i < g[vfmin].size(); i++){
                x = g[vfmin][i].first; c = g[vfmin][i].second;
                if(!uz[x])
                    if(cmin[x] > cmin[vfmin] + c){
                        cmin[x] = cmin[vfmin] + c;
                        pp.first = cmin[x]; pp.second = x;
                        H.push(pp);
                    }
            }
                    uz[vfmin] = 1;

        }
    }
}

void afisare(){
    for(int i = 2; i <= n; i++){
        if(cmin[i] != INF)
            fout << cmin[i] << " ";
        else fout << 0 << " ";
    }
}

int main(){

    citire();
    djikstra();
    afisare();
    return 0;
}