Cod sursa(job #3253608)

Utilizator Ana_22Ana Petcu Ana_22 Data 3 noiembrie 2024 20:04:23
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.22 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#define NMAX 50001
#define INF 1000000000
using namespace std;

vector <pair<int,int>> edges[NMAX];
int d[NMAX];
priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int,int>>> pq;
// M log N

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

void djikstra( int source, int n ) {
    for( int i = 2; i <= n; i++ ) d[i] = INF;
    d[source] = 0;
    pq.push( { d[source], source } );
    while( !pq.empty() ) {
        pair<int,int> pr = pq.top();
        int dist = pr.first;
        int node = pr.second;
        
        pq.pop();
        
        for( auto pr : edges[node] ) {
            int newnode = pr.first;
            int cost = pr.second;
            if( d[newnode] > dist + cost ) {
                d[newnode] = dist + cost;
                pq.push( { d[newnode], newnode } );
            }
        }
    }
}

int main() {
    int n, m, x, y, c;
    fin >> n >> m;
    for( int i = 0; i < m; i++ ) {
        fin >> x >> y >> c;
        edges[x].push_back( { y, c } );
    }
    djikstra( 1, n );
    for( int i = 2; i <= n; i++ ) {
        if( d[i] == INF ) fout << 0 <<' ';
        else fout << d[i] << ' ';
    }
    return 0;
}