Cod sursa(job #2853245)

Utilizator k2y201342asdfadfsafsd k2y20 Data 20 februarie 2022 09:18:07
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.71 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 sol[N];

struct comparator
{
    bool operator()(pair<int,int>a, pair<int,int>b)
    {
        return a.second>b.second;
    }
};

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

    priority_queue <pair<int,int>, vector<pair<int,int> >, comparator> pq;
    pq.push(make_pair(1,0));

    while(!pq.empty())
    {
        int nod=pq.top().first;
        int distMIN=pq.top().second;
        pq.pop();

        if(sol[nod]>distMIN) continue;
        //cout<<pq.top().first<<','<<pq.top().second<<": ";
        la[nod].parcurs=1;
        for(int i=0;i<lsize(nod);i++)
            {
                if(la[m(nod,i)].parcurs) continue;
                int newDist=sol[nod]+val(nod,i);
                //cout<<m(nod,i)<<','<<sol[m(nod,i)]<<'/'<<newDist<<'\n';
                if(newDist<sol[m(nod,i)])
                {
                    sol[m(nod,i)]=newDist;
                    pq.push(make_pair(m(nod,i),sol[m(nod,i)]));
                }
            }
        //cout<<'\n';
    }

}

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(sol[i]==INF)
            sol[i]=0;
        out<<sol[i]<<' ';
    }

    return 0;
}