Cod sursa(job #3246911)

Utilizator MateiAlex24Diamandi Matei MateiAlex24 Data 4 octombrie 2024 19:19:43
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.34 kb
#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
 
using namespace std;

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

const int inf = 1e9; // 10^9
vector<pair<int, int> > v[50005];
int cost[50005];
int inCoada[50005];
class cmp{
public:
    bool operator() (int x, int y) {
        return cost[x] > cost[y];
    }
};
priority_queue<int, vector<int>, cmp> pq;
 
int n, m, x, y, c;
void dijkstra(int nod) {
    for(int i = 1; i <= n; i ++) {
        cost[i] = inf;
    }
    cost[nod] = 0; // costul de la nodul de la care am inceput pana la nodul curent
    pq.push(nod);
    while(!pq.empty()) {
        nod = pq.top();
        for(auto elem : v[nod]) {
            if(cost[nod] + elem.second < cost[elem.first]) {
                cost[elem.first] = cost[nod] + elem.second;
                if(inCoada[elem.first] == 0) {
                    pq.push(elem.first);
                    inCoada[elem.first] = 1;
                }
            }
        }
        inCoada[nod] = 0;
        pq.pop();
    }
}
 
int main() {
    fin >> n >> m;
    for(int i = 1; i <= m; i ++) {
        fin >> x >> y >> c; // muchie intre x si y cu costul c
        v[x].push_back({y, c});
    }
    dijkstra(1);
    for(int i = 2; i <= n; i ++) {
        fout << cost[i] << ' ';
    }
    return 0;
}