Cod sursa(job #2853286)

Utilizator k2y201342asdfadfsafsd k2y20 Data 20 februarie 2022 10:14:28
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.34 kb
#include <bits/stdc++.h>

using namespace std;

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

#define m(i,j) la[i].v[j].first
#define val(i,j) la[i].v[j].second
#define lsize(x) la[x].v.size()
const int N=5e4+5,INF=0x3F3F3F3F;
struct graf
{
    vector <pair<int,int> > v; // nod & cost
    bool parcurs;
} la[N];
int dist[N];

void dijkstra(int n)
{
    for(int i=2; i<=n; i++)
        dist[i]=INF;
    dist[1]=0;

    set<pair<int,int> >dij;
    dij.insert(make_pair(0,1));

    while(!dij.empty())
    {
        int nod=dij.begin()->second;
        int d=dij.begin()->first;
        dij.erase(dij.begin());

        for(int i=0;i<lsize(nod);i++)
        {
            int to=m(nod,i);
            int cost=val(nod,i);

            if(d+cost<dist[to])
            {
                if(dist[to]!=INF) dij.erase(dij.find( make_pair(dist[to],to) ));
                dist[to]=dist[nod]+cost;
                dij.insert(make_pair(dist[to],to));
            }

        }
    }
}

int main()
{

    int n,m;
    in>>n>>m;

    for(int i=1; i<=m; i++)
    {
        int a,b,c;
        in>>a>>b>>c;
        la[a].v.push_back(make_pair(b,c));
    }

    dijkstra(n);

    for(int i=2; i<=n; i++)
    {
        if(dist[i]==INF)
            dist[i]=0;
        out<<dist[i]<<' ';
    }

    return 0;
}