Cod sursa(job #2133473)

Utilizator filip.mihalutMihalut Filip filip.mihalut Data 16 februarie 2018 23:47:16
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.2 kb
#include <iostream>
#include <fstream>
#include <bits/stdc++.h>
#define nmax 50003

using namespace std;

ifstream f ("dijkstra.in");
ofstream g ("dijkstra.out");

vector < pair < int,int > > v[nmax];
set < pair < int,int > > heap;
int INF = 0x3f3f3f3f , n, m ,i , j, x, y, c, next_x,next_c,d[nmax],l;

int main()
{
    f >> n >> m;
    for(i = 1;i <= m;i++)
    {
        f >> x >> y >> c;
        v[x].push_back({y,c});
    }

    memset(d,INF,sizeof(d));

    d[1] = 0;
    heap.insert({0,1});
    while(not heap.empty())
    {
        c = heap.begin() -> first;
        x = heap.begin() -> second;
        heap.erase(heap.begin());
        l = v[x].size();
        for(i = 0;i < l;i++)
        {
            next_x = v[x][i].first;
            next_c = v[x][i].second;
            if(d[next_x] > next_c + c)
            {
                if(d[next_x] != INF)
                heap.erase(heap.find({d[next_x],next_x}));
                d[next_x] = next_c + c;
                heap.insert({d[next_x],next_x});
            }
        }
    }

    for(i = 2;i <= n;i++)
    {
        if(d[i] == INF)
            g << "0 ";
        else g << d[i] << " ";
    }
    return 0;
}