Cod sursa(job #2789136)

Utilizator qubitrubbitQubit Rubbit qubitrubbit Data 26 octombrie 2021 22:20:54
Problema Algoritmul lui Dijkstra Scor 50
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.73 kb
#include <fstream>
#include <vector>
#include <cmath>
#include <iostream>
#include <map>
#include <queue>
using namespace std;

ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
#define inf 5000000001L;

class Graph
{
    struct Edge
    {
        int from;
        int to;
        int cost;
    };

private:
    int cntNodes;
    vector<vector<Edge>> fromToList;

public:
    Graph(int n)
    {
        cntNodes = n;
        for (int i = 0; i < n; ++i)
        {
            fromToList.push_back(vector<Edge>());
        }
    }

    void addEdge(int from, int to, int cost)
    {
        fromToList[from].push_back({from, to, cost});
    }

    vector<long long> dijkstra(int source)
    {
        vector<long long> d(cntNodes, -1);
        d[source] = 0;
        auto cmp = [&](const int &a, const int &b) -> bool
        {
            return d[a] < d[b];
        };
        priority_queue<int, vector<int>, decltype(cmp)> pq(cmp);
        pq.push(source);
        while (!pq.empty())
        {
            int top = pq.top();
            pq.pop();
            for (Edge e : fromToList[top])
            {
                if (d[e.to] == -1 || d[e.to] > d[top] + e.cost)
                {
                    d[e.to] = d[top] + e.cost;
                    pq.push(e.to);
                }
            }
        }
        return d;
    }
};

int main()
{
    int n, m, a, b, c;
    fin >> n >> m;
    Graph g(n);
    while (m-- > 0)
    {
        fin >> a >> b >> c;
        g.addEdge(a - 1, b - 1, c);
    }
    vector<long long> dist = g.dijkstra(0);
    for (int i = 1; i < dist.size(); ++i)
    {
        fout << (dist[i] == -1 ? 0 : dist[i]) << " ";
    }
    return 0;
}