Cod sursa(job #1495227)

Utilizator diana97Diana Ghinea diana97 Data 2 octombrie 2015 19:07:24
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.31 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <algorithm>
#include <vector>

using namespace std;

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

const int INF = (1 << 30);
const int NMAX = 50000 + 1;

int n, m;
int d[NMAX];
vector <int> graf[NMAX], cost[NMAX];
priority_queue < pair <int, int> > pq;

void citeste() {
    int a, b, c;
    f >> n >> m;
    for (int i = 1; i <= m; i++) {
        f >> a >> b >> c;
        graf[a].push_back(b);
        cost[a].push_back(c);
    }
}

void dijkstra(int src, int d[]) {
    int nod, fiu, l, c, c2;
    pair <int, int> p;

    for (int i = 1; i <= n; i++) d[i] = INF;
    d[src] = 0;

    p.first = 0; p.second = src;
    pq.push(p);
    while(!pq.empty()) {
        p = pq.top(); pq.pop();
        nod = p.second;
        c = -p.first;
        l = graf[nod].size();

        for (int i = 0; i < l; i++) {
            fiu = graf[nod][i];
            c2 = c + cost[nod][i];
            if (c2 < d[fiu]) {
                d[fiu] = c2;
                p.first = -c2;
                p.second = fiu;
                pq.push(p);
            }
        }
    }
}

void scrie() {
    for (int i = 2; i <= n; i++) {
        if (d[i] == INF) d[i] = 0;
        g << d[i] << ' ';
    }
    g << '\n';
}

int main() {
    citeste();
    dijkstra(1, d);
    scrie();
    return 0;
}