Cod sursa(job #2870108)

Utilizator anastasei_tudorAnastasei Tudor anastasei_tudor Data 12 martie 2022 09:29:25
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.53 kb
#include <bits/stdc++.h>
#define INF 1000000004
#define NMAX 50004

using namespace std;
ifstream fin ("dijkstra.in");
ofstream fout ("dijkstra.out");

int n, m;
int dp[NMAX];
bool viz[NMAX];
vector < pair <int, int> > G[NMAX];

struct comparare
{
    bool operator() (const int & a, const int & b)
    {
        return dp[a] > dp[b];
    }
};

priority_queue<int, vector<int>, comparare> H;

void citire();
void Dijkstra(int start);
void afisare();

int main()
{
    citire();
    Dijkstra(1);
    afisare();
    return 0;
}

void citire()
{
    int x, y, c;
    fin >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        fin >> x >> y >> c;
        G[x].push_back({y, c});
    }

    for (int i = 1; i <= n; i++)
        dp[i] = INF;
}

void Dijkstra(int start)
{
    dp[start] = 0;
    H.push(start);
    viz[start] = 1;

    while (!H.empty())
    {
        int nod = H.top();
        H.pop();
        viz[nod] = 0;

        for (int i = 0; i < G[nod].size(); i++)
        {
            int vf = G[nod][i].first;
            int cost = G[nod][i].second;
            if (dp[vf] > dp[nod] + cost)
            {
                dp[vf] = dp[nod] + cost;
                if (viz[vf] == 0)
                {
                    H.push(vf);
                    viz[vf] = 1;
                }
            }
        }
    }
}

void afisare()
{
    for (int i = 2; i <= n; i++)
        if (dp[i] == INF)
            fout << 0 << ' ';
        else
            fout << dp[i] << ' ';
}