Cod sursa(job #2141594)

Utilizator jeanFMI - Petcu Ion Cristian jean Data 24 februarie 2018 14:38:17
Problema Algoritmul lui Dijkstra Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.25 kb
#include<iostream>
#include<algorithm>
#include<vector>
#include<unordered_map>
#include<map>
#include<queue>
#include<utility>
using namespace std;

typedef unordered_map< int, vector<pair<int, int> > > Graph;

map<int, int> dijkstra(Graph &G, int start) {
    int N = G.size();
    map<int, int> dist;
    priority_queue<pair<int, int>, vector<pair<int, int> >, greater<pair<int, int > > > heap;

    heap.push(make_pair(0, start));
    while (dist.size() < N) {
        pair<int, int> node = heap.top();
        int d = node.first;
        heap.pop();
        dist[node.second] = d;
        
        for (auto &it : G[node.second]) {
            heap.push(make_pair(d + it.second, it.first));
        }
    }

    return dist;
}


int main() {
    freopen("dijkstra.in", "r", stdin);
    freopen("dijkstra.out", "w", stdout);

    int N, M, x, y, c, i;
    Graph G;

    cin >> N >> M;
    for (i = 0; i < N; i++) {
        G[i + 1] = vector<pair<int, int> >();
    }
    for (i = 0; i < M; i++) {
        cin >> x >> y >> c;
        G[x].push_back(make_pair(y, c));
    }
    
    int start = 1;
    map<int, int> dist = dijkstra(G, start);
    for (auto &it : dist) {
        if (it.first != start) {
            cout << it.second << ' ';
        }
    }

    return 0;
}