Cod sursa(job #1698176)

Utilizator diana97Diana Ghinea diana97 Data 3 mai 2016 22:25:32
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.35 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <set>

using namespace std;

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

const int INF = 0x7fffffff;
const int NMAX = 50000 + 1;

int n, m;
int sol[NMAX];
vector <int> graf[NMAX], cost[NMAX];

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 sursa) {
    int cost_crt, nod1, nod2, l;
    pair <int, int> p;

    for (int i = 1; i <= n; i++) sol[i] = INF;
    sol[sursa] = 0;

    set < pair <int, int> > s;

    p.first = 0;
    p.second = sursa;
    s.insert(p);

    while(!s.empty()) {
        p = *(s.begin());
        s.erase(s.begin());

        nod1 = p.second;

        l = graf[nod1].size();
        for (int i = 0; i < l; i++) {
            nod2 = graf[nod1][i];
            cost_crt = cost[nod1][i] + p.first;

            if (cost_crt < sol[nod2]) {
                sol[nod2] = cost_crt;
                s.insert(make_pair(sol[nod2], nod2));
            }
        }
    }
}


void scrie(int sursa) {
    for (int i = 1; i <= n; i++) {
        if (i == sursa) continue;
        if (sol[i] == INF) sol[i] = 0;
        g << sol[i] << ' ';
    }
    g << '\n';
}

int main() {
    citeste();
    Dijkstra(1);
    scrie(1);
    return 0;
}