Cod sursa(job #2884152)

Utilizator hurjui12AlexandruHurjui Alexandru-Mihai hurjui12Alexandru Data 2 aprilie 2022 14:47:22
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.28 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

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

vector <pair <int, int>> v[50001];

struct el
{
    int c, x;

    bool operator < (const el &alt) const
    {
        return c > alt.c;
    }
};

int d[50001];
priority_queue <el> p;

int main()
{
    int n, m, i, j, x, y, z;
    el na;

    fin >> n >> m;
    for (i = 1; i<=m; i++)
    {
        fin >> x >> y >> z;
        v[x].push_back ({y, z});
    }

    for (i = 1; i<=n; i++)
        d[i] = 1<<30;

    d[1] = 0;
    p.push ({0, 1});

    for (i = 1; i<n; i++)
    {
        while (p.empty() == 0 && p.top().c > d[p.top().x])
            p.pop();
        if (p.empty() == 1)
            break;

        na = p.top();
        p.pop();

        for (i = 0; i<v[na.x].size(); i++)
        {
            y = v[na.x][i].first;
            z = v[na.x][i].second;

            if (d[y] > na.c + z)
            {
                d[y] = na.c + z;
                p.push ({d[y], y});
            }
        }
    }

    for (i = 2; i<=n; i++)
    {
        if (d[i] == (1<<30))
            fout << 0 << ' ';
        else
            fout << d[i] << ' ';
    }
    return 0;
}