Cod sursa(job #2423980)

Utilizator ade_tomiEnache Adelina ade_tomi Data 22 mai 2019 13:31:10
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.44 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

vector<vector < pair<int, int> > > v;

const int INF = 0x3f3f3f3f;
int n, m;
int *d, *dad;

struct ComparePairs { 
    bool operator()(const pair<int, int> &a, const pair<int, int>  &b) const {
        return a.first < b.first;
    }
};

void dijkstra(int start) {
    priority_queue <pair<int, int> ,  vector<pair<int, int> >, ComparePairs> q;
    q.push(make_pair(0, start));

    for (int i = 0; i <= n; i++) {
        d[i] = INF;
        dad[i] = 0;
    }

    d[start] = 0;

    while (!q.empty()) {
        int node = q.top().second;
        int sum = q.top().first;

        if (sum != d[node]) {
            q.pop();
            continue;
        }

        q.pop();

        for (int i = 0; i < v[node].size(); i++) {
            if (sum + v[node][i].second < d[v[node][i].first]) {
                d[v[node][i].first] = sum + v[node][i].second;
                q.push(make_pair(d[v[node][i].first], v[node][i].first));
            }
        }
    }
}


int main() {
    ifstream cin ("dijsktra.in");
    ofstream cout ("dijsktra.out");

    cin >> n >> m;
    v.resize(n + 1);
    d = new int(n + 1);
    dad = new int(n + 1);

    for (int i = 0; i < m; i++) {
        int a, b, c;

        cin >> a >> b >> c;
        v[a].push_back(make_pair(b, c));
    }

    dijkstra(1);

    for (int i = 2; i <= n; i++) {
        cout << d[i] << " ";
    }

    return 0;
}